The invention discloses a cutting tool detecting method for computer numerical control equipment. The computer numerical control equipment comprises a cutting tool measuring instrument used for conducting preliminary detection on cutting tools to be detected. The cutting tool detecting method comprises the steps that the cutting tool measuring instrument is adopted for conducting preliminary detection on the cutting tools to be detected; a cutting tool detecting block is provided and fixed to a workbench of the computer numerical control equipment, the surface of the cutting tool detecting block is finish-milled, and the finish-milled surface of the cutting tool detecting block is set as a reference surface; the cutting tools to be detected are sequentially used for milling the surface of the cutting tool detecting block by a preset depth value; the practical depth values of milling of the cutting tools to be detected on the surface of the cutting tool detecting block are detected; and the milling depth deviations of the cutting tools to be detected are obtained, the deviation values of the cutting tools to be detected are compensated in the subsequent machining process. By adoption of the cutting tool detecting method for the computer numerical control equipment, the machining precision of the computer numerical control equipment is effectively improved, the machining requirement of high-precision parts is met, operation is convenient, and promotion and popularization in the industry are facilitated.