LIQUID FEEDING PUMP AND LIQUID FEEDING METHOD

Provided is a technology for reducing the capacity of a liquid feeding pump and enabling liquid feeding with little pulsation. A liquid feeding pump according to the present disclosure is provided with: a first plunger pump having a first plunger; a second plunger pump having a second plunger and connected in series with the first plunger pump; a pressure sensor disposed downstream of the second plunger pump; and a control unit that accepts the input of a liquid discharge pressure measured by the pressure sensor and that controls the driving of the first plunger and the driving of the second plunger. The control unit calculates the rate of change in the pressure of the liquid on the basis of the past compression distances of the plunger for when the liquid was compressed by the first plunger pump and the pressure at the completion of compression, predicts the compression distance of the first plunger on the basis of the rate of change in pressure and the present discharge pressure, and determines the timing at which the compression performed by the first plunger will be completed on the basis of the predicted compression distance.