This paper developed a novel method which involved binocular stereo vision to measure the model ablative pattern directly regarding the ablative pattern which was under testing in the arc heated wind tunnel. This method used the speckle correlation to process the data, combined sub-pixel correlation can make the results achieve very high precision. The real planar measuring results was obtained after the test was done on a flat model.The calibrate precision of the measure system is 0.02 mm. The results verified that this method can be useful for the analysis of the model characterize related with ablative time.