Illuminance distribution of LED spherical arrays is studied by theoretical analysis and simulation. The optimal layout of the LED spherical array is founded by changing the angle, the ball radius, and the power of different LED. The uniformity of illumination of the LED spherical array is verified, which is better than LED planar array. In addition, the illuminance distribution of indoor ground surface illuminated by LED spherical array with different parameters and the related curves are obtained. The LED spherical array mentioned in this paper can be useful in the application of indoor visible light communication.