The invention discloses a radar pulse compression filter optimization design method applied to random signal waveforms. The method mainly solves the problem of pulse compression filter optimization design under constraint conditions of a main lobe width, processing gain loss and a sidelobe level. The radar pulse compression filter optimization design method includes the steps that firstly, new signal vectors are designed for radar transmitting signal waveforms and the filter length, and a signal matrix is established on the basis of the new signal vectors and is adjusted according to the pulse compression main lobe width at the same time; secondly, the allowable maximum processing gain loss is processed combined with pulse compression to form a constrained optimization equation; finally, the optimal filter coefficient under the constraint conditions is solved and obtained through a convex optimization tool. The optimal sidelobe level can be obtained under the conditions of the given pulse compression filter length, the main lobe width and the processing gain loss, meanwhile the method has the advantage of being irrelevant to signal modes, and the method is applied to signal pulse compression filter design of linear frequency modulation, phase encoding, frequency encoding and the like.