The key of MIR (Micropower Impulse Radar) technology lies in how to design an effectual receiver circuit. Based on correlation detection and detection threshold, MIR receiver circuit is designed, with emphasis on the receiver signal processing circuit. It is simulated and verified with satisfying results to get a flat 3dB passband for the amplitude frequency characteristics of the band-pass, low and high-pass filter and Q value more than 5 for the 50 Hz trap filter.The design achieves the theory design requirements with simple structure, low cost and good performance. It has definite practical value in ultrawideband technique.