Aligning and fixing the fiber and laser device is an important work in butterfly laser module packaging. Assembling these two component by laser welding is to achieve reliable and stable weld joint. However, during the welding process, rapid solidification of the welded region and the associated material shrinkage causes the fiber position moved. The relative movement between fiber and laser is called post-weld-shift(PWS). A few micrometers PWS makes coupled power lost. Therefore, minimizing the PWS between fiber and laser is a key research topic in butterfly laser module packaging. We can correct the PWS minimal by fiber shift inspect. But it has a difficult of space limit in butterfly laser module packaging. In this study, a video camera with image acquisition system was used to measure the PWS. We also used a mirror image to solve the problem of space limited. The PWS inspection result has matched our simulation. This method can successfully inspect the PWS in butterfly laser module.