The method of gear geometric model construction from surface reconstruction is searched to widen ways of the gear reverse engineering modeling.The model reconstruction combining the advantages of Imageware and Pro/E is studied and the solid model based on point-cloud is finally obtained by taking a planetary gear with higher motion accuracy and contact precision as the object in a heavy-duty truck bridge

and the method is reconstruction of one tooth surface and some feature curves in Imageware and then construction of the whole surface of the gear in Pro/E.The result show that the method of building gear CAD model through surface reconstruction is effective.