Aiming at the characteristics of magnetron of airport surveillance radar, such as short operation time, complexity and nonlinear vibration signal, a fault reasoning method based on T-S fuzzy fault tree model was proposed to realize fault reasoning analysis of magnetron of radar receiving and receiving system. A T-S fuzzy fault tree fault inference model is constructed by using the field expert’s opinion expressed by fuzzy number language set. The experimental results show that compared with the traditional manual fault detection method, this method can make more comprehensive and efficient inference analysis for the magnetron fault events. This method provides a new idea for the application of magnetron fault reasoning analysis in engineering.