The invention discloses piston type fertilizer liquid mixing equipment for agriculture irrigation. The piston type fertilizer liquid mixing equipment comprises a vehicle frame, a backflow pipe, a suction main pipe, a mixing tank, a machine frame, a piston rod, a piston type mixer, an irrigation spray head and a flow spraying bulge, wherein the machine frame is connected with the mixing tank through a fixed frame; the piston type mixer is arranged in a mixing cavity of the mixing tank, the flow spraying bulge is arranged at the bottom part of the mixing tank, the middle part of the bottom end of the flow spraying bulge is connected with the backflow pipe, the backflow pipe is connected with the output end of a liquid injection pump, the input end of the liquid injection pump is connected with the suction main pipe, and the suction main pipe is respectively communicated with a liquid suction pipe A and a liquid suction pipe B; a liquid drain hole is formed in the bottom end of the mixingtank, and is communicated with a liquid drain pipe. The piston type fertilizer liquid mixing equipment has the advantage that the piston type mixer is driven by the piston rod to do reciprocating movement, then the fertilizer liquid in the mixing cavity is mixed, the liquid injection pump sucks the fertilizer liquid out of a liquid suction port, and the fertilizer liquid is sprayed via a flow spraying hole of the flow spraying bulge, so as to effectively avoid the settlement or accumulation of the fertilizer, improve the mixing efficiency of the fertilizer liquid, and reach the effect of convenient irrigation.