An optical coupler module includes a semiconductor substrate disposed on the print circuit board; a reflecting trench structure formed on the semiconductor substrate; a reflector formed on a slant surface of the reflecting trench structure; a strip trench structure formed on the semiconductor substrate and connecting with the reflecting trench structure; a thin film disposed on the above-mentioned structure. The optical coupler module further includes a signal conversion unit disposed on the semiconductor substrate and the position of the signal conversion unit corresponds to the reflector; and an optical waveguide structure formed in the trench structures. The optical signal from the signal conversion unit is reflected by the reflector and then transmitted in the optical waveguide structure, or in a reverse direction to reach the signal conversion unit.