Abstract: In order to evaluate the rolling contact fatigue performance of the current technological level 8Cr4Mo4V material steel ball in the aviation main bearing, using a 9.525 mm diameter 8Cr4Mo4V material steel ball as the research carrier, the contact fatigue test under different stress levels are carried out by a five-ball fatigue testing machine. The test data is effective by analysis of steel ball failure modes and failure fracture evolution. At the same time, in order to analyze the test data, a simple program processing method is proposed, and obtain the different failure probability fatigue life and P-N fatigue curve of the steel ball. The results show: The rolling contact fatigue life of steel balls of 8Cr4Mo4V material used in aviation main bearings of current technological level is more than 3 times of the fatigue life of steel balls of foreign materials tested abroad in 1992. Through the analysis of the fatigue test data of the 9.525 mm diameter 8Cr4Mo4V material steel ball, the undetermined coefficient of the stress life function is solved, and the contact fatigue life under different stress levels can be predicted.