The invention discloses a locking wellhead forming method of needle roller bearing retainer, which comprises the following steps: firstly, a plurality of openings are punched on a retainer body; then at least a pair of molds are inserted into the adjacent openings on the retainer body, two symmetrical forming protrusions are arranged on the opposite surfaces of the molds, the forming protrusions are aligned with the sidewall of the opening; finally, the pair of molds are extruded toward each other to deform the sidewall of the opening between the pair of molds, so as to form a locking wellhead with the ability to be inserted by the needle roller. The locking wellhead forming method has the advantages of visual locking wellhead forming, easy control of lock needle amount, stable process, less liability to retainer dead needle or dropped stitches, thus improving the pass rate of the retainer.