The research is to umte the traditional optical method with the modern quantizing 1mage technique ,and to calculate mterferogram usmg the advance quantizing 1mage processmg means and fitting mterfero gram method with Zernike polynomials so that the evenness and other technical parameters of surface of optical plane glass can be quickly and precisely measured. Using the results of the research in the system to mspect the surface of plane glass , the precision of the system IS about ).,/100 and sensitivity reaches about À./1000 .