The 6 n mile visible pilot lamp system is designed based on the theory of atmospheric transmission, photometry and application of geometry optics. LEDs are arranged in linear order and through analyzing the luminescence characteristics of LED, the appropriate system of light collecting, collimating and dodging are designed and optimized so that the design can distribute the light in vertical direction within 10 degrees and in horizontal direction within 3 degrees in a uniform manner in 6 n mile away. The design can be applied to help ships with different drafts to choose the right channel.