And we analyzed the effect of the big gun erect axis incline trunnion axis is out of the vertical of the erect axis and the big gun axis is out of the vertical of the erect axis to measuring accuracy 对矢量转轴公式进行了推导,并利用它计算出了火炮竖轴倾斜、炮耳轴与竖轴不垂直、炮膛轴线和炮耳轴不垂直三种误差对测量精度的影响。