The utility model relates to a supplementary trainer for standardizing action of trip swimmer upper limbs, locate human buoyancy subassembly and set up in backplate subassembly buoyancy subassembly one end, that be used for restricting human upper limbs home range including the cover, the backplate subassembly includes that baffle and symmetry set up in first backplate, the second backplate at baffle both ends. The utility model discloses a superior effect lies in: baffle, first backplate and second backplate enclose into trip swimmer upper limbs arc rowing's streamlined region, the baffle prevents that arm pull is dark excessively, first backplate, second backplate are used for limiting arm pull, prevent that arm pull is too big, and especially the upper limbs action route the during breaststroke is regional to be favorable to standard trip swimmer, and the effectual training efficiency that has improved has shortened the training time, has lengthened trip swimmer's the endurance time.