Abstract: The de-embedding technology is implemented through the idea that views the measurement circuit as an equivalent network cascade in radio frequency. Usually, the working frequency is below 6 GHz. For it can realize the accurate measurement of the device under test (DUT), it has been the focus for many tests. But when it refers to the de-embedding technology in microwave measurement, the present study is not enough. In order to get the actual value of the DUT, based on the principle of error model parameters correction, this article takes the Gyro-TWT output window as an example to verify the principle and finally gets the actual results of the DUT after de-embedding whose working frequency is on Q band. This principle gets rid of the resonance problem, and shows that the de-embedding principle has a high accuracy in microwave measurement. This article introduces the de-embedding principles and concretes the implementation methods, which have important significance on microwave de-embedding.