Aimed at the existing problem of radar distance null point, a radar distance calibration module scheme based on bulk acoustic wave microwave delay line is presented in this paper, and a method to reduce insertion loss of bulk acoustic wave microwave delay line, enhance delay time, and extend operating frequency range is also proposed, based on which a radar distance calibration module is developed. Actual test results show that this module has high test accuracy and law requirement of fields, which can be widely used in radar production and maintenance.