Abstract: The impact of the different half-intensity light angles on the LED array maximum interval was discussed. The illumination data of LED unit was calculated and simulated using Matlab. The corresponding simulation graphics were given. The simulation results show that the maximum interval between the LED light sources is independent of the power. Since the simulation results agree with the theoretical values, the LED optical model established in the calculation has good credibility. These results are useful in the modeling and application of LED multiple arrays such as round, rectangular and oval.