The invention discloses a gas-liquid mixing device. The device comprises a catalyst grid, a cold hydrogen distributor, gas-liquid distributors, a distribution disc, a redistribution disc and a shell,wherein the catalyst grid, the cold hydrogen distributor, the gas-liquid distributor, the distribution disc and the redistribution disc are all fixed on the inner wall of the shell; and the cold hydrogen distributor mainly comprises a cold hydrogen distribution pipe and a straight nozzle, the cold hydrogen distribution pipe comprises distribution ring pipes and distribution straight pipes, the distribution ring pipes and the distribution straight pipes are respectively located in the same plane, the distribution ring pipes are distributed in a concentric circle shape, the distribution straightpipes and the distribution ring pipes are communicated in a crossed mode, the distribution pipe is provided with straight nozzles arranged in pairs at intervals along the axis of the distribution pipe, one end of one distribution straight pipe is provided with a cold hydrogen inlet, and each straight nozzle is a cold hydrogen outlet. The device is simple and compact in structure, cold hydrogen can be more uniformly distributed on the total cross section of the reactor and can be fully mixed with reaction oil gas, uniform mass transfer and heat transfer are guaranteed, and the heat transfer efficiency of media in the reactor is improved.