The invention discloses a closed microwave high-temperature sintering roller kiln, in particular a tunnel roller kiln with length of 10 to 50meters, and hearth sectional area of 0.06 to 0.3m<2>. The kiln comprises a main kiln body, a microwave transmission system, a turning channel mechanism, a roller power system, and a kiln door interlocking opening and closing system; the main kiln body is formed by connecting a water draining section, a preheating section, a sintering section, a heat preservation section, a quick cooling section, and a slow cooling section in turn; the turning channel mechanism is mainly formed by a material loading and unloading section and a residual-heat utilization blank drying section and comprises a turning channel, a turning channel roller, and a power system; the power system can poke a pushing plate from the outlet of the main kiln body onto the turning channel and feed the pushing plate into the inlet of the main kiln body through the residual-heat utilization blank drying section; and an inner roller for transmitting the material pushing plate, which is driven by the roller power system, is arranged on the bottom of an inner cavity of the main kiln body. The closed microwave high-temperature sintering roller kiln saves energy and reduces consumption and is environmental-friendly, the shrinkage of the sintered products is consistent and the sintered products have high size consistency, the yield is high, the production efficiency is high and the production cost is low.