Aiming at the problems of traditional manual alignment time-consuming, low yield and poor consistency of transparent optical communication devices, the edge model and coupling model of transparent optical communication devices are established by studying the automatic assembly requirements of transparent optical communication devices. The influence of edge error on coupling loss is analyzed by overlapping integral method, and an edge detection of transparent optical communication devices based on digital image is designed programme. The experimental results show that the scheme can detect the edge of transparent optical communication device in complex background well, and can meet the accuracy requirements of alignment deviation. It provides support for the research of intelligent alignment system of automatic assembly of transparent optical communication device, and has important engineering application significance.