Novel liquid chromatogram liquid conveying pump

The invention discloses a novel liquid chromatogram liquid conveying pump. A novel pump structure is adopted. According to each pump, a motor drives a ball screw, the ball screw changes rotary motion into linear motion, then a ball screw nut pushes a push rod to do reciprocating motion, and rotation of the screw is controlled precisely by a stepping motor. According to the novel liquid chromatogram liquid conveying pump, the liquid conveying precision of a constant flow pump can be improved substantially.