NOVELTY - Microbial solid fermentation reaction device comprises a feeding inlet, a reactor, a stirring device and a discharge port. The reactor is a hollow rectangular body, where one end at the upper end of the rectangular body is provided with feeding inlet. Two corners of the reactor at the lower part of feeding inlet are in arc shape. The side face at the other end of the rectangular body is provided with a discharging port lifting plate and a feeding outlet. The stirring device comprises a stirring paddle, a stirring shaft and an electrical motor, whose one end is connected to electrical motor.    USE - Used as a microbial solid fermentation reaction device.    ADVANTAGE - The device is highly efficient, simple in structure, easy to operate, and economical; and achieves complete mixing of the material under aerobic conditions, by reciprocating stirring in the stirring device.    DETAILED DESCRIPTION - Microbial solid fermentation reaction device comprises a feeding inlet, a reactor, a stirring device and a discharge port. The reactor is a hollow rectangular body, where one end at the upper end of the rectangular body is provided with the feeding inlet. Two corners of the reactor at the lower part of the feeding inlet are in arc shape. The side face at the other end of the rectangular body is provided with a discharging port lifting plate and a feeding outlet. The stirring device comprises a stirring paddle, a stirring shaft and an electrical motor. One end of the stirring shaft is connected to the electrical motor. The stirring shaft is uniformly distributed with stirring paddles. The stirring shaft passes by the reactor. The shafts are distributed parallelly from the inlet end to the outlet end of the reactor. One end of the stirring shaft is connected to the electrical motor and the other end is distributed outside the reactor wall. An INDEPENDENT CLAIM is also included for using method of the device, comprising (i) crushing biomass and microbial inoculum, and uniformly mixing, then passing the mixed material to the reactor by the feeding inlet, and allowing to stand in a first stirring device for 12 hours; (ii) fermenting the solid material for 12 hours, and starting stirring device function at the first stirring device, then rotating the stirring device in a clockwise direction for odd number of times for 6 minutes, and rotating the stirring device in an anti-clockwise direction for even number of times for 6 minutes; and (iii) performing solid fermentation for 1 hour after the stirring device rotates along the discharging direction, passing the material from the first stirring device to a second stirring device, and adding fresh material to the first stirring device in empty space of the reactor by the feeding inlet, till the material is passed to the last stirring device, and performing fermentation in the reactor, then lifting the discharge port plate in the reactor, passing the material discharged from the reactor, and obtaining an organic fertilizer collected by the discharge port along the direction of the stirring device.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic representation of the microbial solid fermentation reaction device.