Light modulator for underwater lamp

The utility model relates to a light modulator for an underwater lamp. The light modulator comprises a power supply, a stabilizer, a light modulation operation board, and an electronic light modulator connected with an underwater lamp. The stabilizer has stabilizer power terminals connected with the power supply, light source lightening output terminals, and alarm signal output terminals. The light modulation operation board includes light modulation operation plate power terminals connected with the power supply, alarm signal input terminals connected with the alarm signal output terminals, and a power switch with two ends connected with the light modulation operation plate power terminals and the alarm signal input terminals. With the light modulator, the brightness adjustment of the underwater lamp can be realized conveniently and thus the underwater lamp can realize displaying of different brightness, thereby realizing adaption to various fishes. When the light modulator is in use, the underwater lamp can be adjusted to the proper brightness by using the light modulator without the need to replace underwater lamps with different brightness, thereby lowering the using cost.