Speed prediction method of numerical control system, control method of numerical control system and numerical control system

The invention discloses a speed prediction method of a numerical control system, a control method of the numerical control system and the numerical control system. The speed prediction method comprises the following steps that a plurality of first sub-processing paths of a cutter for processing a workpiece are obtained; the preprocessing speed of a cutter on the current first sub-processing path is calculated, and rotary cutter center point transformation is carried out to obtain a current second sub-processing path; the average speed and the average acceleration of the cutter on the current second sub-processing path are calculated and verified, so that whether the preprocessing speed is adjusted or not is judged; the final speed of the cutter on the previous first sub-processing path is used as the initial speed of the current first sub-processing path; and according to the initial speed and the preprocessing speed, the final speed of the cutter on the current first sub-processing path is calculated and out