Abstract: In response to the issues of simple monitoring methods, low efficiency, and the inability to reflect the overall surface deformation of waterproof sealed walls, a monitoring scheme for the deformation of waterproof sealed walls in underground water reservoirs of coal mines is proposed. Based on the principle of binocular positioning, deformation calculation formulas for single-point protrusion and depression on the surface of the sealed wall were provided, along with the calculation logic for three-dimensional cloud map imaging of surface deformation. The cubic spline interpolation method was chosen for interpolation fitting, forming a three-dimensional deformation model of the entire surface of the waterproof sealed wall. A non-contact surface deformation monitoring device was designed, which generated structured light images through a light projection module and projected them onto the surface of the waterproof sealed wall. Two light-receiving modules formed a binocular system to receive the reflected structured light images from the sealed wall surface. These images were then analyzed based on the deformation calculation logic. Simulation test results indicated that single-point deformation monitoring and three-dimensional cloud map imaging performed well, effectively reflecting the overall deformation of the monitored object and enabling timely monitoring of its safety status by management personnel.