Based on the perturbation theory of microwave resonator,the resonant cavity as a sensor model for measuring semiconductor and luminescent materials is established.HFSS simulatio n software is used to simulate the parameters and structure of the resonator.The simulation results show that the microwave resonator has the electric field form and electric field intensity which accord with the experimental requi rements when rectangular holes are used.The experimental results also show that the sample has a strong signal in the cavity with rectangular coupling holes.Different samples are placed in resonant cavity and irradiated by nanosec ond pulse laser.The ideal dynamic curves are obtained,and the practicability of TM012mode is proved.It lays a f oundation for the next step to measure the dielectric constant and conductivity of the samples and other physical param eters.