The utility model discloses an accurate device of light source test under water of test position control, including pond, first driving system, second driving system, lamp source system, detecting system, first driving system, second driving ystem installation can realize the left and right sides, front and back, the removal of upper and lower direction and the rotation on the horizontal direction on the pond, lamp source system is fixed in first driving system, detecting system fixes in second driving system, and the light is sent in the lamp source, shines on the detecting system to this detects lamp source performance parameter. The utility model discloses the characteristic of used pond water steadily, and is undulant little, and the testing ring border is stable, and lamp source system and detecting system can rotate on removal of the three degree of freedom and horizontal direction through having driven a vehicle system assurance, and the displacement coordinate of every degree of freedom all can accurately arrive 1mm, and the turned angle accuracy is to 0.1, and the capability test in lamp source can be realized carrying on under water by lamp source system and detecting system's watertight device.