Seal structure, rubber material, surface feature of rubber and contact metal, lubricating grease type between rubber and contact metal and other factors need to be considered in the process of wheel bearing seal development. Because fluid dynamic lubrication under multi-factor is very complicated, it is difficult to simulate this working condition accurately by CAE. France HUTCHINSON, Japan UMC, Japan NOK and other well-known seal companies evaluate sealing design by seal test, so the seal test is significant. Equally, seal failure analysis is very significant. At present, the evaluation of seal test still stays at“pass” or “no pass”. Lack of systematic method for the analysis of the failure of the hub bearing which can be used in the actual vehicle after the assembly line makes the design improvement of the sealing become blind and inefficient. The purpose of this paper is to study an accurate and effective seal failure analysis method, the paper analyzed root causes of seal failure from the perspective of raw information acquisition, diagnosis, wear trace analysis, residual interference acquisition, abrasion reconstruction and aging analysis systematically, and the 8 kinds of seal failure causes were summed up. The study can provide a direction for the design or optimization of the seal, so that the work of the seal development will become highly efficient and targeted.