The invention discloses a kitchen ventilation system based on an air curtain and filtration. The system consists of a fresh air section, an air curtain section and an air exhaust section, wherein the fresh air section consists of a fresh air port, a PM2.5 filter, an air feeder, an injector air-supplement branch pipe and the like; the air curtain section consists of a reducing pipe, a gas stove, an angle-adjustable air curtain, a hot air curtain blowing-in branch pipe and the like; the air exhaust section consists of an exhaust hood, a one-way check valve, an exhaust fan and an air outlet; after being filtered, one path of fresh air is conveyed to the injector air-supplement branch pipe so as to be used for injection of the gas stove, one path of fresh air is conveyed to the air curtain for cooking in summer and transitional seasons, and another path of fresh air is conveyed to the hot air curtain blowing-in branch pipe so as to regulate the temperature of the air curtain and meet the heat comfort requirement of a human body; the jet current and fume of the air curtain are discharged to the outdoors by virtue of the exhaust hood. The system can be used for achieving the effects of insulating heat, reducing indoor cooling load, improving the cooking comfort degree and health degree, preventing cooking fumes from spreading into a horizontal living room, improving the combustion efficiency of the system and the like, is beneficial to formation of an open kitchen and ensures that the architectural space is fully utilized.