XMind does not support synchronization at this time.
If you want to open your desktop mind maps on Android mobile, you can transfer the maps from your computer to your mobile by using a third-party cloud service like Dropbox, OneDrive, and Google Drive.
Below are the steps of file transfer (OneDrive as an example).
1. Download OneDrive both on your computer and your phone.
2. Upload your desktop mind map to OneDrive on your computer.
3. Launch and update OneDrive on your phone.
4. Find and tap the map, then you can open it with XMind for Android.
Please note that if you are unable to select XMind to open the map directly, you can download and save the map to the folder of local/XMind/Workbook. Then you can open the map from XMind for Android.