A manufacturing method of a crimping terminal includes a terminal supply step of supplying the crimping terminal to a crimping position with a wire by a terminal supply device, the crimping terminal including a terminal connection portion, a wire connection portion to be crimped onto the wire, and a joint portion linking side walls of the terminal connection portion and the wire connection portion, a support step of supporting a bottom portion of the crimping terminal supplied to the crimping position by a first mold, a crimp step of deforming the wire connection portion while relatively moving toward the first mold, and crimping the wire connection portion onto the wire by a second mold, and a regulation step of regulating a width of the joint portion so as not to be wider than a width of the terminal connection portion, by sandwiching the joint portion from both sides in a width direction when the second mold crimps the wire connection portion by a regulation portion.