Aiming at the optimization of signal-to-noise ratio of indoor visible light multi-user communication, an optimization algorithm based on genetic algorithm is proposed. By quantificationally analyzing the delay characteristics of each light emitting diode(LED) lamp signal emission path as the measurement value of gene contribution to signal-to-noise ratio, the maximum signal-to-noise ratio contribution retention and minimum signal-to-noise ratio contribution elimination methods are used to improve the crossover and mutation process of genetic algorithm. The simulation results reveal that for the LED selection problem, the proposed method converges faster and obtains better signal-to-noise ratio than the general evolutionary algorithm.