The invention discloses a method for determinacy shape correction processing based on the surface shape error slope. The method comprises the first step of inputting the surface shape error slope and a height removal function of a to-be-processed optical part; the second step of converting the height removal function into a slope removal function; the third step of utilizing a deconvolution calculation method to calculate a dwell time function according to convolution relations of the slope removal function, the surface shape error slope and the dwell time function required for determinacy shape correction processing control; the fourth step of performing the determinacy shape correction processing on the surface of the to-be-processed optical part based on the calculated dwell time functions. The dwell time necessary for the processing control is calculated by directly using surface shape error slope data obtained through measurement, the surface shape error slope does not need to be converted into the surface shape error height, so that the conversion error caused by the fact that the surface shape error slope is converted to the surface shape error height is avoided, and the method is favorable for improving the determinacy in the processing process and improving processing accuracy.