The invention discloses a multi-level plunger variable displacement oil well pump. The multi-level plunger variable displacement oil well pump comprises a pump barrel, a fixed valve pair, a travelling valve pair, an eccentrically arranged valve pair, a plunger and the like, wherein a hollow cavity of the pump barrel is divided into a first cylindrical pump cavity and a second cylindrical pump cavity which communicate with each other; the inner diameter of the first cylindrical pump cavity is smaller than that of the second cylindrical pump cavity; the fixed valve pair is connected with one end of the first cylindrical pump cavity; the plunger is arranged in the pump barrel, and the shape of the plunger is matched with the hollow cavity of the pump barrel; the travelling valve pair is arranged at a liquid inlet of the plunger in the first cylindrical pump cavity; the eccentrically arranged valve pair is arranged in the plunger in the first cylindrical pump cavity and is close to the position of the travelling valve pair; a delivery valve cover is connected with the top end of the plunger in the second cylindrical pump cavity; and a pull rod is connected with the delivery valve cover and stretches out of the pump barrel. According to the multi-level plunger variable displacement oil well pump, the plunger and the pump barrel both adopt a two-level structure and correspond to different pump diameters separately, achieves switching of the different pump diameters through different strokes, and correspond to two displacements separately, and the displacement range of the oil well pump is greatly broadened.