Abstract: This paper introduces a new type of pre-discharge tube cavity structure, which uses two quartz tubes. The size and connection mode of the two tubes are specially designed, which can effectively solve the problem of increasing the recovery time of receiver protector caused by the existing new radar with long pulse width and large pulse power, and shorten the recovery time to less than one tenth of the previous one. The recovery time index is closely related to the radar blind area, so this study will effectively reduce the radar blind area range and improve the radar performance. This paper introduces the design principle, method and test results of this kind of structure.