For most RF microwave systems, microwave power is an essential evaluation index. For small and medium microwave power source systems, in order to meet the testability of the system, it is necessary to increase the quantitative detection of the output power. In this paper, a simple, practical and economical design method of microwave power detection module is introduced in detail. The method realized the detection of the high precision peak power, pulse repetition frequency and pules width by linear detection，sample hold，data sampling and software calibration methods. The test data are compared with the actual measurement of power meter and oscilloscope, and the measurement precision of the module developed by this method is verified.