Design/methodology/approach Based on the high-speed conditions of a mechanical seal with a low-viscosity fluid, a multi-factor coupled lubrication model of a mechanical seal is established. The perturbation Reynolds equation set is derived using the perturbation method, and the effects of turbulent flow and inertia on sealing performance are discussed. Findings The results indicate that turbulence significantly influences the dynamic characteristics of low-viscosity fluids under high-speed conditions. Originality/value The results of the dynamic characteristics presented in this study are expected to provide guidance for the design of mechanical seals.