Manufacturing method of wire harness

A manufacturing method of a wire harness which includes at least one bundle of an electric wire group in which a plurality of electric wires are linearly arranged, and a damming part made of a resin material, wherein the damming part surrounds a part of the electric wire group in an extending direction of the electric wire group, and wherein the damming part includes an outer periphery shape part according to an inner peripheral shape of an electric wire group insertion part, the manufacturing method comprising:

• disposing a part of the one bundle of the electric wire group in a harness housing part and mold clamping an upper mold and a lower mold in which the harness housing part is formed on a pair of divided surfaces;
• and
• performing low pressure injection of a larger amount of molten resin than a volume of a cavity into the cavity, so that the resin material with which the cavity is filled protrudes from gaps between flat deburring surfaces and adjacent electric wires,
• wherein the harness housing part includes the cavity so as to mold the damming part and includes the flat deburring surfaces which clamp an outer periphery of the one bundle of the electric wire group at both outside end parts of the cavity which face each other in the extending direction of the electric wire group.