A high power X-band T/R module has been designed in the paper. The T/R module theory and scheme are expounded, the main technological indexes of The T/R module are calculated, such as peak power, receive gain, noise figure and so on. The transmit peak power is about 45.6 dBm. The receive gain is about 30 dB. The noise figure is slightly larger than 3 dB, which provides a reference for the design of high power T/R module