The computational models and its parameter identification methods of wind-rain coupling loads on bridges and structures are presented in this paper with the aspects of joint probability distribution of wind and rain, wind and rain separated action and coupled effects on steady and unsteady forces. According to the calculation preciseness, the function of Gumbel and Copula has been selected to describe joint probability distribution of wind and rain intensity after various attempts. Firstly, Two type simple mathematic models have been tried in wind and rain separated action, including raindrop impact model and equvalent air density model, and both of them show the fact that it may be accurate enough to neglect rain influence while only considering direct rain loading action. Furthermore, through suspended 2-D scaled models wind tunnel tests under the condition of wind and rain coupling loading environment, in which high-frequency dynamic force-measured balance and artifical rainfall system were utilized, showing that rain effect should not be neglected in steady and unsteady force models with considering coulped action of wind and rain on bridges and structures. Finally, using updated wind and rain coupling simulated equipment, systemic parameter analysis of wind-rain excited phenomena of stay cables were rechecked, illustrating the influence of spatial angle, dynamic character, in-coming wind velocity and different density combination of wind and rain.