To provide construction machinery capable of more efficiently utilizing the energy of return hydraulic oil from a hydraulic actuator. The present invention is provided with: an engine 11; a hydraulic pump 12 that is driven by the engine 11; a hydraulic actuator 17 that is driven by fluid discharged from the hydraulic pump 13; a discharge pressure sensor 12d that detects the discharge pressure from the hydraulic pump 13; a hydraulic regenerative motor 18 that is driven by the return hydraulic oil from the hydraulic actuator 17; a flow meter 18e that detects the flow rate of the return hydraulic oil; a flow dividing valve 50 that controls the rate of inflow to the hydraulic regenerative motor 18; a controller 15 that controls the flow dividing valve 50 according to the discharge pressure detected by the discharge pressure sensor 12d and the flow rate detected by the flow meter 18e; a regenerative generator 19 that generates electric power by being driven by the power of the hydraulic regenerative motor 18; and a motor generator 13 that assists drive of the engine 11 by the electric power supplied from the regenerative generator 19.