Abstract: This paper presents a laser optical fiber system of detecting the variable figure area with CCD,Introducing optic image and computer processing techniques. Adopting a good method that it can calculate quickly and simultaneously the figure boundary locus surrounding area recorded by CCD which comes into being gradually, realizing the simultaneous indications of imagery and its area.This system is char acteristic of high efficiency and auto mation when we detecting the extent of the ice-melt in the front of car window.It shows a meaning of practice. On engineering measuring,it is of reference value.