A backpack type small berry picking machine comprises a back frame, a miniature gasoline engine, a centrifugal type clutch, a steel wire flexible shaft, a secondary gear drive mechanism, an eccentric vibration mechanism, a housing, a front annular handle, a rear handle, and branch vibrators; the miniature gasoline engine is arranged on the back frame through a vibration isolation rubber pad; an output shaft of the miniature gasoline engine is connected with an input end of the steel wire flexible shaft through the centrifugal type clutch; a square joint of the output end of the steel wire flexible shaft is connected with a square interface of an axle drive bevel pinion of the secondary gear drive mechanism; the eccentric vibration mechanism comprises an upper crank, a lower crank, an eccentric adjustable camshaft, a dual-face guide rail, an upper reciprocating oscillating lever and a lower reciprocating oscillating lever; the branch vibrators are respectively fixed on the front ends of the upper and lower reciprocating oscillating levers; the front portion and rear portion of the housing are respectively provided with a front annular handle and a rear handle; the rear handle is provided with a speed regulator; the speed can be regulated so as to allow the small berry branches to generate different frequency vibrations, and the vibration force can separate the small berries from the branches.