In order to design a wire bonder, a vision position module on LabVIEW platform is needed. In this paper, an improved Otsu method is achieved based on LabVIEW and dynamic-link library (DLL). By analyzing the mechanism of dynamic-link library, this paper introduced the key technique of achieving image segmentation on LabVIEW by using DLL. Finally, experiments are undertaken by using a kind of IC chip. It’s shown that, the quality of resulting images achieved by LabVIEW is similar as that achieved by VC++, and the segmentation costs less than 50ms, about 20ms more than that achieved by VC++.