Wheels are the most important bearing parts of train, and wheel’s operation influences safety of the train’s motion. On the premise of investigating and summarizing the application and development of the tread profile's scratch detection technology at home and abroad, the paper describes a multi-channel data acquisition system using Cyclone serials FPGA as the core control module, which achieves communication to Digital Signal Processor (DSP) at the back-end. Ultimately, the field test demonstrates that the system can measure damage of the wheel tread and ensure the safe operation of trains.