Xiaomi Mi MIX 3 (perseus) Firmware Flash File Download [Stock Rom]

The Xiaomi Mi MIX 3 (codename perseus), launched in 2018, was a masterpiece of design and engineering from Xiaomi’s experimental MIX series. Its defining feature was an innovative magnetic slider mechanism; with a satisfying click, the user could slide the screen down to reveal the dual front-facing cameras. This clever design achieved a stunning, truly bezel-less 93.4% screen-to-body ratio on its beautiful Super AMOLED display. Powered by the flagship Qualcomm Snapdragon 845 chipset and featuring a premium ceramic back option, the Mi MIX 3 was a true work of art. This page provides the official fastboot ROMs for China and Global, along with the essential TWRP custom recovery for advanced users.

Important: You must verify your device is the standard 4G Mi MIX 3 (perseus). This firmware is not compatible with the later Mi MIX 3 5G (andromeda), which has a different chipset, or the Mi MIX 2S (polaris). Flashing the wrong firmware will hard brick your phone.

Quick Device Specs

• Device: Xiaomi Mi MIX 3 (perseus)
• Release year: 2018
• Chipset: Qualcomm Snapdragon 845
• Display: 6.39″ Super AMOLED, HDR, Full Screen Display
• Battery: 3200 mAh, 18W wired & 10W wireless charging
• Original MIUI: Android 9 (Pie), MIUI 10

Required Downloads

Official ROMs & Custom Recovery

How to Flash Official ROM (Mi Flash Tool)

This is a quick checklist for this device. For a complete tutorial on installing drivers, unlocking the bootloader, and troubleshooting, please read our master guide:

Read Our Ultimate Guide to Mi Flash Tool

Use this method to unbrick your phone or restore official MIUI firmware.

1. Boot into Fastboot mode (Power + Volume Down).
2. Extract the official firmware (.tgz file) and select the main folder containing the /images directory in Mi Flash Tool.
3. Select clean all for a safe installation (you can use clean all and lock to return to a fully stock, locked state).

How to Install TWRP & Its Purpose

Use this method if you want to install custom ROMs, root your phone, or create full backups.

What is TWRP? TWRP (Team Win Recovery Project) is a powerful custom recovery that replaces your phone’s basic stock recovery. It is the essential tool needed to perform advanced modifications, such as installing community-developed ROMs (like Pixel Experience or LineageOS), gaining root access with Magisk, or creating complete system backups (known as Nandroids).

Disclaimer: This is an advanced process. Proceed at your own risk.

1. Unlock the Bootloader: This is the mandatory first step. Use the official Mi Unlock Tool.
2. Flash TWRP:
   • The TWRP download is a .zip file containing the recovery .img and flashing scripts. Extract it.
   • Boot your phone into Fastboot mode (Power + Volume Down) and connect it to your PC.
   • Run the fastboot-flash-recovery.bat script from the extracted folder to install TWRP.
3. Boot into TWRP: After flashing, immediately boot into recovery by holding Power + Volume Up to prevent the stock ROM from overwriting it.
4. From here, you are ready to perform advanced tasks like flashing custom ROM .zip files found on community forums like XDA.

FAQs

Q1. What is the difference between the Mi MIX 3 (perseus) and the Mi MIX 3 5G (andromeda)?
While they look identical, the 5G version (andromeda) features a more powerful Snapdragon 855 processor and a 5G modem. The standard Mi MIX 3 (perseus) uses the Snapdragon 845. Their firmwares are not interchangeable.

Q2. Is the magnetic slider durable?
Yes. Xiaomi officially rated the neodymium magnetic slider mechanism for over 300,000 actuations, making it very robust for years of normal use. It provides a satisfying tactile feedback that motorized sliders lack.

Q3. What was the final official update for the Mi MIX 3?
The Mi MIX 3 launched with Android 9 Pie and received its final major OS upgrade to Android 10. The MIUI 12.5 version for the China region was the last significant software update for this model.

Q4. I don’t see a custom ROM link, so why is TWRP provided?
TWRP is the universal key that unlocks the ability to install any custom ROM. We’ve provided the TWRP file as the essential first step for users who wish to explore the rich custom ROM community for the Mi MIX 3, which includes popular ROMs like Pixel Experience, LineageOS, and others.

Troubleshooting

• Drivers: If your PC does not recognize the phone in fastboot mode, reinstall the Xiaomi USB drivers and run Mi Flash Tool as Administrator.
• Fastboot errors:
  • “error: not catch checkpoint” → This common error means you have selected the wrong folder. In Mi Flash Tool, be sure to select the parent folder that was created when you extracted the .tgz file, not the images folder inside it.
  • “Anti rollback error” → You are attempting to flash an older firmware version than what is currently on the device. Xiaomi’s Anti-Rollback Protection (ARB) prevents this.
• TWRP Issues:
  • TWRP asks for a password → This means your phone’s storage is encrypted. The standard fix is to go to the “Wipe” menu in TWRP and choose “Format Data”. This will erase everything on your internal storage.
  • Stuck on boot after flashing a custom ROM → Reboot to TWRP, perform a full wipe (Cache, Dalvik, System, Data), and then re-flash the ROM .zip file.