Abstract: Machine vision technology is widely used in egg non-destructive sensory quality detection. Quickly getting the image edge will help more efficiently identify the geometric characteristic parameters. Inspired by the dichotomy algorithm to rapidly solve equations, this paper proposed the same idea to rapidly detect the image edge and set up the theoretical basis for it. The image was composed by rows of pixels and each row was named Line Image. The paper used the line image information to build an equation, which would transform the problem of edge detecting into the equal problem of equation solving. Besides, the paper gave the implementation steps about how to program in application. Experimental results show that the method can detect egg image edge, and the detection efficiency had been improved about 20 times, which will provide the egg automated industry with higher speed.