A metal halide lamp for a deep water submersible comprises a reflecting cover, an upper lamp tube, a lower lamp tube, a rear end cover and sealing rings. The upper lamp tube, the lower lamp tube and the rear end cover are sequentially mounted on the rear portion of the reflecting cover, and the sealing rings are mounted between all the above parts. A glass cover and a lamp base are sequentially mounted in the upper lamp tube, the glass cover is placed in the reflecting cover, and a bulb is mounted on the lamp base. The front end of the lower lamp tube is connected with a mounting plate, and the rear end cover is provided with a connecting plate. A trigger and ballast are sequentially connected to a mounting plate, and the bulb, the lamp base, the trigger and the ballast are electrically connected. The metal halide lamp for the deep water submersible is easy and convenient to mount, and solves the mounting problem. Moreover, the illuminating brightness can be adjusted according to actual needs, the process of glass cover die sinking and the process of radiating and stress are optimized, and good insulation performance and radiating performance are achieved. Meanwhile, the problems of deep water pressure resistance, great depth sealing and the like caused by structure problems are solved. Accordingly, the metal halide lamp for the deep water submersible greatly lowers the production cost, improves the reliability of products, and can work under the hostile sea conditions.