The turbine engine blade tip clearance measurement is very important for improving engine performance. Engine rotor blade radial clearance control is the important link of improving the pneumatic performance and efficiency of the engine. Measurement precision of traditional tip clearance measurement sensor is limited. Based on resonant cavity theory, this paper designed a new type of microwave blade tip clearance sensor working in 15 GHZ. The sensor can realize the resonant frequency associated with tip clearance and convert tip clearance measurement to resonant frequency measurement to improve the measurement precision. On the basis of theoretical analysis, this paper modeled and simulated using HFSS. The simulation results show that the sensor has simple structure, good performance, elevates obviously the measure precision compared with the traditional microwave sensor and meets the demand of high precision measurement.