In order to further optimize the structural parameters of asymmetric continuous rigid bridges, taking an asymmetric continuous rigid bridge as an example, the Midas Civil finite element model of the whole bridge was established, and the sensitivity analysis of the influence of different parameters of the asymmetric continuous rigid bridge on the deflection of the key sections of each span was carried out, and a piecewise Gaussian curve fitting method for calculating the precamber of the bridge was proposed. Under the premise of minimizing the error of each node, the piecewise Gaussian curve was used to fit the deflection of each node into a smooth curve through Origin, and the calculation formula for the bridge precamber was obtained. The polynomial fitting and nonlinear fitting results were compared and analyzed. The results show that the shrinkage creep effect, concrete bulk density and tension control stress have significant effects on the deflection, while the concrete elastic modulus is very small, and the larger the span of the main beam is, the higher the sensitivity to the first three factors is. Moreover, the coefficient of bridge precamber ^R2 fitted by the piecewise Gaussian curve method reaches more than 0.980 0, which is significantly better than that of the traditional method. This study reveals the difference law of span diameter sensitivity of deflection parameters of asymmetric continuous rigid bridges, and proposes that the piecewise Gaussian curve fitting method is used to set the pre-supply degree of asymmetric bridges, which can provide a reliable theoretical basis and technical reference for ensuring the driving comfort and structural stress safety of such bridges in long-term operation.