The invention relates to the technical field of hydraulic engineering, and particularly relates to a rotational-control constant-flow hydraulic oil pump. The rotational-control constant-flow hydraulic oil pump comprises a working pump, a control valve body, a control pump, an adjustment valve, a flow distribution valve, an adjustment valve element, a locking nut, an adjustment guide sleeve, a valve element limit plug, a flow distribution valve element, a return spring and a spring limit plug, wherein the working pump is installed at the front end of the control valve body; the control pump is installed at the rear end of the control valve body; the working pump is serially connected with the control valve body and a rotational-control pump to form the rotational-control constant-flow hydraulic oil pump; the working pump and the rotational-control pump are coaxial; and the adjustment valve and the flow distribution valve are installed in the control valve body. Compared with an existing hydraulic system of an engineering truck, the rotational-control constant-flow hydraulic oil pump disclosed by the invention has the advantages of being small in size, light in weight, low in use and maintenance costs, and the like.