The rail grinding control technology was taken as the research object. The principle of PID control algorithm was analyzed, and by contrasting the similarities and differences between the position mode PID algorithm and the increment mode PID algorithm, the design of rail grind control system based on the increment mode PID algorithm was put forward, and the hardware principle and software flow of this control system was introduced in detail. With building the corresponding test platform, the system basic function and the corresponding performance were tested. The test result showed that the rail grinding control system based on the increment mode PID algorithm could grind rail steadily and reliably with high control precision, short adjustment time, high real time and perfect grinding effect, which would have good market apply prospect in the future.