The electrical hydraulic speed control system of coal mining mechanical plays an important role to ensure the coal mine production. Based on the analysis about the principle of the electrohydraulic control system of constant power automatic speed control, the mathematical model of the selftuning PID control was built by using the RBF neural network selftuning PID control strategy. By MATLAB/GUI simulation platform, the output error between the real output and the model output was less than 5%.It is shown the designed electric hydraulic constant power speed regulation selftuning PID control system has higher tracking precision and response characteristics, by which high precision and fast speed regulation control can be achieved.