A tray piston type rocking fluid pressure-feeder driven by a crank connecting rod mechanism comprises a support housing (5), a plurality of tray piston type rocking execution devices (2), a fluid inlet and outlet passage system, a cooling system, and a driving force generation system. The fluid inlet and outlet passage system comprises a fluid passage (6, 6a, 6b), a pipe orifice and a valve. The fluid passage (6, 6a, 6b) is in communication with a working chamber (4c). The cooling system is a mechanism for forced cooling and/or natural heat dissipation of components of the fluid pressure-feeder. The support housing (5) is provided with n (n≥1) tray piston type rocking execution devices (2), rotating centerlines of rocking trays (36) of the n tray piston type rocking execution devices (2) are distributed on the same circumferential diameter around the rotating center of a driving crankshaft (10), and the rotating centerlines of the rocking trays (36) are perpendicular to a plane of a support wallboard (34). A system for mechanically driving pistons to act on a fluid load comprises a prime motor and a crank rocker mechanism. The reciprocating rocking range of an angular travel of rocking piston plates (40) is approximately 0 to 150 degrees, and the fluid pressure-feeder is applied to driving the pistons to pressure-feed a fluid for pumping work; and the pressure-fed fluid is gas or liquid.