This paper deals with probabilistic sensitivity analysis for a semi-rigid joint of continuous web plate based on correlations analysis. Firstly, a numerical study was carried out by the software package ANSYS, the finite element analysis was validated compared with experimental results. Secondly, parameters sensitivity analysis was carried on by applying ANSYS Probabilistic Design Analysis. Considering the correlations in primary parameters, all random parameters are varied at the same time based on Monte Carlo simulation. An especial expression between geometric parameters and moment-rotation was discussed. Thirdly, the moment-rotation model of the joint was attained. The composite constant of the moment-rotation model is determined by partial derivative of any parameter from the model. It is concluded that the parameters of the model have notable physical meaning and the proposed model should be accurate and acceptable.