Abstract: In order to study the bending elastic properties of GFRP gates under gradient pressure, six GFRP gate panel specimens with different panel thicknesses, grid structure parameters and calculated spans were designed. A gradient load stacking test was carried out under the boundary conditions of fixed support on one pair of opposite sides and free on the other pair of opposite sides. The influence laws of different structural parameters on the bending deformation characteristics of GFRP gate panel specimens were mainly analyzed. The test results show that the gradient load loading process of the GFRP gate panel is divided into three stages, namely the initial elastic deformation stage, the interface micro-damage stage, and the elastic recovery stage. Increasing the thickness of the panel and the grid can effectively reduce the degree of bending deformation of the GFRP gate panel. Among them, increasing the thickness of the grid can most effectively improve the flexural deformation capacity of the GFRP gate panel. When adopting a long-span design, the deformation at the center of the bottom of the panel needs to be strictly controlled. Based on the single trigonometric series method, a deflection deformation function of the GFRP gate panel under hydrostatic pressure was constructed, and the theoretical analytical solution of the deflection function was derived based on the principle of minimum potential energy. The results show that the error between the theoretical calculation value and the test value is controlled within 14.00%, and the established calculation formula can well predict the flexural bearing capacity of such GFRP gate panels.