A thermo-elastohydrodynamic lubrication transient simulation model for reciprocating rod seals was developed. In the model, the viscoelastic response of rubber materials under transient operating conditions was considered, and the transient Reynolds equation was solved. The stiffness matrix method, which is more stable and effective than the traditional influence coefficient method, was used to solve the problem of fluid - solid coupling in reciprocating sealing. The transient temperature distribution of the sealing system was calculated, and the viscosity of the fluid film was corrected according to the calculation result.