An assembly apparatus for an optical transceiver has a positioning device and an assembly device. The assembly device has a base, a transverse adjustment mechanism adjustably mounted on the base, a clamping mechanism mounted on the transverse adjustment mechanism for clamping a control circuit board, a height adjusting mechanism adjustably mounted on the transverse adjustment mechanism, a longitudinal adjustment mechanism adjustably mounted on the height adjusting mechanism and element holding mechanism adjustably mounted on the longitudinal adjustment mechanism for holding a optical element. Accordingly, an optical transceiver can be conveniently assembled and tested with the assembly apparatus.