With the advantages of anti-interference and no accumulated error, bionic polarization heading measurement has important military significance and research value for autonomous navigation. However, the heading robustness is seriously affected by the accuracy of skylight polarization model and the existing methods all use the Rayleigh scattering model without considering the atmospheric depolarization. Therefore, this paper proposed an innovative method of polarization heading measurement based on Berry model to considering the influence of depolarization neutral points. And this model is improved by controlling the neutral points with correction coefficients to realize high-robustness heading measurement. On this basis, the improved Berry model is further used to calibrate the sensor parameters outdoors, which separates the skylight polarization model error from the sensor error without expensive instruments and complicated processes, and improves the heading measurement accuracy. In the experiments with changing solar altitude, the average of heading error STD after field calibration is 20.86% lower than that of Berry model and 92.85% lower than that of Rayleigh model, which shows great advancement in actual measurements.