Abstract: With the continuous iteration of inertial navigation system technology and products, reliable evaluation methods for its positioning accuracy have become more and more important. This paper mainly discusses the principles and characteristics of three algorithms, including the 95% position circle probability error statistical method(95%CEP), the true root mean square statistical method(TRMS), and the 95% confidence statistical method, and analyzes the relationship between the three, and verifies it through the number imitation truth and experiments, and concludes that: 95%CEP=1.73×TRMS when the evaluation test scheme is designed, and this relationship does not change with the data distribution and the number of sample points; When the data distribution obeys the normal distribution, the 95% confidence level is basically consistent with the statistical value of the 95 P method, and the relationship with TRMS is relatively fixed when the normal distribution is large, and the change is greater in the case of small samples and non-normal distribution; As a positioning error index in foreign applications, TRMS has the characteristics of simple evaluation method, clear physical significance, and few statistical experimental parameters, which has advantages over the other two algorithms.