Small chain-type ditching machine

A small chain-type trencher, it includes engine fixed on frame, output shaft of the engine is connected with one central axle and a hydraulic pump through belt pulley driving device and chain wheel driving device; said central axle is connected with a chain cutter main axle through a chain wheel driving device or belt pulley driving device, the chain cutter main axle is connected with chain cutter device used for excavating through chain cutter main chain wheel; pressure oil exports of said hydraulic pump are connected with the hydraulic motors of hydraulic cylinder and drive bridge separately through multiport valve and two ways, extensible lever device on the hydraulic oil cylinder is connected with the chain cutter device; said engine output shaft is connected with a central axle and ahydraulic pump separately through belt pulley driving device, said central axle is connected with a chain cutter main axle through a chain wheel driving device; the belt pulley driving device connecting said motor output axle