There is provided a production method of a resin composite module for a vehicle, which includes a resin module substrate, and a silicone-based polymer hard coat which is formed on the resin module substrate. The method includes forming the hard coat by coating a silicone-based polymer onto the resin module substrate, and radiating an ultraviolet ray onto at least a part of a surface of the hard coat such that a hardness thereof becomes 0.8 GPa or more as evaluated by a nanoindentation method. The radiating the ultraviolet ray uses a light source unit which includes a light source and emits an ultraviolet ray having a wavelength of 360 nm or less from an emission surface thereof and radiates the ultraviolet ray onto the surface of the hard coat while a distance from the emission surface to the surface of the hard coat is 10 mm or less.