The utility model provides an injection system is prepared to clear water for ROV. Set up in ROV, ROV is including taking the photograph camera, master manipulator and auxiliary engine tool hand, this system includes a coarse filter, a muddy water pump, a high pressure filter, a solution tank and a clarified water pump that connects gradually through an aqueduct, the muddy water pump with the clarified water pump is connected with the motor respectively, the clarified water pump can pass through the aqueduct is with the clear water through injection portion blowout, injection portion is including communicateing through one or two cross valve respectively first branch pipe, second branch pipe and the third branch pipe of aqueduct, every a shower nozzle is all connected to the tip of branch pipe, wherein three shower nozzle sets up respectively in the below of taking the photograph camera, master manipulator, auxiliary engine tool hand. Above -mentioned injection system is prepared to clear water for ROV can filter near the feculent sewage in ROV, becomes the clear water, again by the shower nozzle blowout, makes near ROV sea water part become limpid, improves visibility and shoots the quality to obtain comparatively clear image information.