Taking the optimization of the active guide vane airfoil shape of the pump turbine as the objective, the active guide vane shape was parameterized by B-splines, and in order to ensure the structural strength of the active guide vane airfoil, the pivot diameter of the guide vane and the shape of the guide vane along the height direction of the vane were kept unchanged in the optimization of the active guide vane of the pump turbine, a total of 12 control points of the active guide vane airfoil shape up and down, and the control points were changed by the use of Latin hypercube sampling to realize the geometric reconfiguration of the active guide vane airfoil shape in the given interval. The geometrical reconstruction of the guide vane airfoil was achieved by changing the control points in a given interval by using Latin hypercube sampling, and the influence of 360 different guide vane airfoils on the efficiency of the pump-turbine was analyzed with the efficiency as the objective function, and the comprehensive loss coefficients were introduced by taking into account the flow mechanisms of the pump and the turbine in two working conditions. Numerical simulation was used to validate the prediction data of the RSM HDMR surrogate model for the active guide vane airfoil. The results showed that the optimized guide vane profile shifted the high-efficiency point backward without changing the energy characteristics of the internal flow at the original pump operating point, and at the same time, it improved the internal flow characteristics of the turbine operating condition, reduced the loss of turbulence kinetic energy, and reduced the energy dissipation at the tail, and improved the efficiency by 0.379 percentage points, which proved that the optimization method of this guide vane airfoil profile was feasible, and it can provide methodological and theoretical guidance for the design and modification of the pump turbine's movable guide vane airfoil profile.