Abstract: The main characteristics of TMS320F2810 were introduced and its application in path length control (PLC) technology in ring laser gyro (RLG) was discussed, numerically simulated and experimentally implemented. TMS320F2810 is characterized by high integration, good processing capability, low power dissipation and high performance price ratio, which is very convenient for digital integration and compact design of the RLG control system. Alternative current (AC) path length control system was implemented by this digital signal processing (DSP) chip and some associated circuits, and proportionalintegral-derivative (PID) control parameters were optimized based on Simulink simulation. PLC system was implemented and its software and hardware diagrams were presented, some optimized PID parameters (Kp=0.048, Ki=0.059, Kd=0.013) were obtained, and the whole control loop was experimentally verified. The experimental results show that the performance of the RLG is improved obviously, the bias stability is reduced from 0.025/h to 0.014/h after PID parameter optimization, and the anticipated objective is realized by the proposed control loop.