The present invention relates to a method and apparatus for measuring the position of a ferrule of a laser module. The apparatus comprises an XYZ stage, a base, a receiving portion and a laser displacement meter (LDM). The XYZ stage is used for moving in three-dimensional directions. The base has a first slot by which the base is detachably connected to the XYZ stage. The receiving portion is fixed to the base and has a second slot. The laser displacement meter is used for measuring the distance between the ferrule and the laser displacement meter. The laser displacement meter is detachably connected to the receiving portion in the second slot. Whereby, the quantitative measurement and correction to the effect of the postweld-shift (PWS) on the fiber alignment shifts in laser-welded laser module packaging is achieved. Therefore, the reliable laser modules with high yield and high performance used in low-cost lightwave transmission systems may be developed and fabricated.