A water level line equation under the coupling action of complete pumping-recharge confined well group was derived using the mirror image and superposition principle. Besides, based on the water level equation, an optimization design method for the deep foundation pit dewatering-recharge system was proposed, taking the allowable deformation of pit and surrounding environment as the main constraints. Taking the deep pit of a subway station as an example, the mathematical modeling and solving process for optimizing the number and assign position of pumping as well as the recharge well points were described. The results show that optimization design can not only ensure the safety of surrounding environment (nearby buildings etc.) and the normal operation of the dewatering project, but also reduce the project cost, which will be helpful for the same dewatering project.