an assembler mechanism for picking up and presenting one workpiece to another for precise bonding notwithstanding the motions of transportation includes a support seat , a first picking member , a first driving member , a second picking member , and a positioning assembly . the first picking member is mounted on the support seat and fetches a first workpiece when driven by the first driving member . the second picking member is connected to and also driven by the first driving member to fetch a second workpiece . the positioning assembly is mounted on the support seat , and includes a positioning member , a movable member located corresponding to the positioning member , and a second driving member connected to the movable member . the movable member can be driven by the second driving member toward or away from the positioning member to achieve unvarying and stable presentations .