In the pursuit of increased THz laser output power and higher beam quality, hybrid metal-mesh output coupler is designed and fabricated. The advantages of hybrid metal-mesh output coupler and its structure are described in this paper. The model of metal-mesh is studied to evaluate the transmittance. g/2a=76 ?m/20 ?m and g/2a=76 ?m/10 ?m are chosen to fabricate hybrid metal-mesh output coupler, and its THz transmittance is evaluated by Far Infrared Rays(FIR) Fourier transform spectroscopy. This study and former researches show that the transmittance of metal-mesh gets higher with the increase of 2a.