The invention discloses a full-fermentation non-crusting methane device. The full-fermentation non-crusting methane device is composed of a base, a fermentation tank body and a top cover, wherein the fermentation tank body is connected to the upper surface of the base, a slag hole and a drain valve are formed in and arranged at the bottom of the fermentation tank body, a heating device is arranged on an inner wall of the tank body, a fermentation chamber is formed in the inner space, the top cover is connected to the top of the fermentation tank body, return pipes and feed ports are arranged on and formed in the top cover, the feed ports are connected with feed port covers, a gas storage chamber is formed below the center feed port cover, an anti-floating grate is arranged at the bottom of the center feed port cover, and a gas guide pipe is connected to the center feed port cover. The full-fermentation non-crusting methane device has the advantages of novel design, no crusting of fermentation of raw materials, no need of stirring, high feed speed, good compression resistance, insulation and sealing performances, less heat loss and high gas yield and can be normally used in winter, the materials are simultaneously fed through a plurality of feed ports, and the methane raw materials, especially straws are manually compressed from the plurality of feed ports, so that the dry matter content of methane is increased.