Hydraulic plunger pump with various variable control functions

The invention discloses a hydraulic plunger pump with various variable control functions. The hydraulic plunger pump with the various variable control functions comprises a plunger pump 1, a flow piston 8 and a flow control valve 4; pressure oil Pp flows from a outlet of the plunger pump 1 into a working cavity m1 at the small end of the flow piston 8, so that the flow piston 8 can move to the right to reduce the displacement of the plunger pump, and Pp pressure synchronously acts on a bearing block assembly 7 through an inner channel r2 of the flow piston 8. According to the hydraulic plunger pump with the various variable control functions, a plurality of functions such as load sensitive control, constant power control and pressure cutoff control can be synchronously achieved as working requirement; in addition, single control function can be achieved; meanwhile, different constant power control variable pressure points, pressure cut-off control variable pressure points and load sensitive control pressure difference and the like can be set according to the requirement.