在Fuchs-Sondheimer薄膜理论（F-S理论）和修正的价带分裂模型的基础上,考虑晶格散射、杂质散射和表面散射,通过求解弛豫近似下的Boltzmann方程,利用并联电阻模型从理论上研究了p-型异质外延金刚石膜的压阻效应,给出了压阻效应的计算表达式,从理论上得到了和实验一致的压阻效应的主要特性.提出了应力作用下分裂带间距变化的模型,对大应力时饱和压阻的理论和实验误差给出了合理解释. Based on the Fuchs-Sondheimer theory (FS) and the modified valence band splitting model, the lattice scattering, impurity scattering and surface scattering are considered. By solving the Boltzmann equation of relaxation approximation and using the parallel resistance model theoretically The piezoresistive effect of p-type heteroepitaxial diamond films was given and the piezoresistive effect was calculated. The main characteristics of the piezoresistive effect were obtained theoretically and experimentally. The variation of splitting distance Model, the theoretical and experimental error of saturated piezoresistive when large stress is given a reasonable explanation.