A straight driving reciprocal rotary screw pump comprises a rotor, a stator, a pump base under the rotor, a fuel inlet valve (1) and a fuel outlet valve (2) on the pump base, and an universal coupler, a connecting axle (1), a connecting axle, (2), a screw couple, and a spline couple which are distributed from up to down. The universal coupler is connected with the upper end of the rotor, the universal couple is arranged with the pump base around, the pump base is disposed with the valve (2) and the valve (1), the screw couple comprises a screw axle, a screw muffle, a rotation ball block, and a ball, and the spline couple comprises a spline axle, a spline muffle, a ball block, and a spline ball. The invention has high producing efficiency and wide application.