Three-section all-in-one rectangular anaeroic digestor

The invention relates to a three-section all-in-one rectangular anaeroic digestor comprising a distribution region, a reaction region and a three-phase separation region, wherein the cross section of the digestor is rectangular and respectively provided with the distribution region, the reaction region and the three-phase separation region from bottom to top, and the distribution region, the reaction region and the three-phase separation region are integrated; the distribution region comprises a bottom plate, the lower part of a side wall and a feeding pipe, wherein the upper surface of the bottom plate is connected with the side wall lower part; the reaction region is defined by the middle of the side wall, two sides inside the reaction region are oppositely provided with a first baffle plate and a second baffle plate from bottom to top, the reaction region is divided into three region chambers, and a gas collecting chamber is arranged at the upper part of each region chamber; and the three-phase separation