The invention provides a high temperature methanation reactor, which comprises a reactor cylindrical body. The reactor cylindrical body includes a reactor external cylindrical body (3), a reactor internal cylindrical body (4) and a jacket layer (5) between the internal and external cylindrical bodies. The upper part of the reactor cylindrical body is provided with a reaction gas inlet (1) and a gas distributor (2), and the lower part is equipped with a gas collector (8) and a reaction gas outlet (9). The jacket layer (5) is filled with a high temperature refractory material. The reactor cylindrical body is loaded with a catalyst bed (6) inside. An inert filler (7) fills the space between the gas distributor (2) and the catalyst bed (6) and the space between the catalyst bed (6) and the gas collector (8). The reactor internal cylindrical body (4) of the reactor provided in the invention is a high temperature resistant stainless steel material, and is hard to crack and come off under a thermal shock, thus avoiding local clogging of the catalyst bed. The reactor is also provided with the gas distributor, the gas collector and the inert filler, so that a feed gas can pass the catalyst bed uniformly, and the product gas can leave the reactor uniformly.