Dynamic parametric inversion plays an essential role in evaluating the health ststus of pump room structure, Huai'an third station was taken as the engineering background for pump structure dynamic parameter inversion. According to the measured first order frequency and the measured acceleration peak value, parameter inversion of pump room structure was carried out on bases on improved genetic algorithm. The more reasonable calculation model was obtained by comparing the effects of the material parameters of pump structure inversion between simplified model and spring constraint model. Reasonable calculation model was more in line with the actual situation of the project and could improve the accuracy of finite element analysis, so as to establish a good foundation for the inversion analysis. The results show that the spring constraint model is more realistic and the result is more accurate than the simple model.