The geological environment of long and deep buried tunnel is complex and changeable. During the construction, the fault fracture zone is prone to geological disasters such as water burst, sand burst, mud burst and collapse. Therefore, advanced geological forecast is particularly important. TSP203 advanced geological prediction technology has become one of the most widely used geophysical exploration methods because of its advantages of long prediction distance, high resolution and high reliability. This paper expounds the basic principles and methods of TSP203 forecast system, and combined with the example of GanQing Tunnel 1# Slope Mine, the comparison of the forecast results with the actual excavation geological conditions further verifies the accuracy of TSP203 forecast system.