Stable light intensity output of high-power LED light source as the goal, a kind of high-precision visibility meter transmitter system is built to achieve the stability of the output of the high-power light source. A bunch of scattered light is the feedback signal of optical power control circuit. Integrated circuits and high-precision devices are used to compose the conditioning and controlling circuit to achieve the dynamic adjustment of the current. The thermostatic control circuit takes parallel connection, monitors and controls the temperature of the light source device and key circuit devices. The experimental results show that the system is stable, relative error of transmitter output intensity is close to 1‰.