Based on Zernike polynomials fitting, the measurement errors posed by optical axis deviation, rotation angle and active area on different types of high-precision surface were analyzed and the experimental verifications were conducted respectively. The results show that the measurement is not sensitive to the rotation angle and active area, the cost of calibrated rotation angle can therefore be reduced, while the impact of optical axis deviation on measurement precision is rather significant, which should be strictly adjusted before the test on high-precision surface.