The invention relates to a stone slab grinding processing device, and belongs to the technical field of stone slab processing equipment. The stone slab grinding processing device comprises a worktable, a grinding machine and a movable cart, wherein a guide rail for left-right movement of the movable cart is installed on the worktable, a stone slab installation block is arranged on the movable cart, a press plate matched with the stone slab installation block is arranged above the stone slab installation block, a power mechanism for vertical movement of the press plate is arranged on the movable cart and corresponds to the press plate, the power mechanism comprises a supporting frame, a hydraulic cylinder and a pushing frame of a framework structure, the pushing frame is fixed to the press plate, a cylinder body of the hydraulic cylinder is installed on the supporting frame, a piston rod of the hydraulic cylinder is fixed to the pushing frame, the supporting frame is installed on the movable cart, and a dust removal mechanism is arranged above the grinding machine. By means of the technical scheme, the stone slab grinding processing device is simple in structure, dust is controlled in the stone slab grinding process, the work environment is good, as a result, the working enthusiasm of workers is improved, and production efficiency is obviously improved.