The invention discloses a jet flow fertilizer pump of a spring water draining device, which is composed of a jet flow component with a spring outer water draining device, a piston group, and a cylinder body, wherein the piston group is mounted in the cylinder body and a pushing cavity, a reset cavity, and fertilizer liquid cavity are formed; two output openings of the jet floe component are connected with the pushing cavity and the reset cavity respectively. According to the invention, the spring water draining device guarantees the stability of the jet flow and the reliability of the water draining; the wall attaching of the jet flow and the load commutated technology are utilized to push the piston group to move circularly, so as to realize the process of fertilizer jetting and fertilizer absorbing, improve the reliability and durability of a commutated mechanism, simplify the structure of the piston group and the cylinder, and improve the integral sealing property; the jet flow fertilizer pump is driven by hydraulic power in an irrigation pipeline, is convenient to mount and use, and is suitable for meeting fertilization requirements in irrigations of micro-irrigation, spray irrigation, low-pressure pipeline and the like.