High precision perpendicularity measurement of internal surfaces of frame parts is one of the most difficult problems in manufacturing. A novel method based on wave-front interferometer to measure the internal surfaces of frame parts is introduced in this paper, and the influencing factors in the measurement are also discussed theoretically. The experiment results show that the method can achieve high perpendicularity measurement accuracy of 0.6". Considering the distribution of the perpendicularity errors derived, the measurement results can be used in error correction machining of the parts.