69 kilometers. According to Baidu map, the journey from Lanxi County to Harbin is 69 kilometers, and the driving time is 1 hour 15 minutes, passing through Heida Highway and Harbin Expressway. Specific bus routes:

1. First enter Heida Highway and drive for 42.4 kilometers.

2. Secondly, enter Heha Expressway 10.7km, and then enter Suiman Expressway for 4.0km. ..

3. Finally, enter Songbei Avenue, drive 4.3 kilometers, and drive 300 meters from century avenue to Harbin to reach the destination Harbin.