The invention relates to a concrete stirrer with high stirring efficiency. The concrete stirrer comprises a base, a first supporting plate, a second supporting plate, a main body, a control room, a discharge box, a control mechanism, a discharge mechanism and a turnover mechanism, wherein the control mechanism comprises a lifting air cylinder, a fixed plate, a first bearing, a first rotary shaft, a first bevel gear, a sleeve, a second bearing, a second bevel gear, a telescopic air cylinder, a drive motor, a third bevel gear and a third bearing; the discharge mechanism comprises a rotary motor and a screw; and the turnover mechanism comprises a turnover motor, a speed reducer, a first belt wheel, a second belt wheel and a transmission belt. The concrete stirrer adopts dual stirring modes which are simultaneous and reverse, and discharge adopts a screw squeezing type discharge method, so that discharge stability is improved; and moreover, during discharge, concrete is stirred again through a screw in a reversible mode, and the concrete stirrer further can regulate the position of a discharge hole; and the base of the concrete stirrer is equipped with universal wheels, so that travelling is convenient.