The invention discloses a speed control method and a speed control device and relates to the technical field of a computer. A nonlinear neural network model can simulate non-linear relationship between velocity instructions under different environments and speed values; a current velocity instruction and historical velocity instructions within a preset time as well as historical velocity values are input to the nonlinear neural network model to obtain a corrected velocity instruction, wherein the corrected velocity instruction is obtained by carrying out correction on the current velocity instruction according to the non-linear relationship between the velocity instructions and the speed values; and the corrected velocity instruction is input to a system based on PID control to obtain an expected speed value, thereby improving speed control accuracy and precision.