The invention discloses a small-flow reel type irrigator water turbine, and aims to provide a reel type irrigator water turbine which is high in efficiency, small in energy consumption, simple in structure and low in production and manufacture cost. The small-flow reel type irrigator water turbine comprises a water inlet, a spray nozzle, a turbine cover, a turbine casing, a rotary wheel, a drive shaft and a water outlet, wherein a water inlet of the turbine casing is connected with a water inlet pipe, and a water outlet of the turbine casing is connected with a water outlet pipe; the inside of the turbine casing is a round structure, the water inlet and the water outlet of the turbine casing are cast to form a tapered structure, and the conical spray nozzle is mounted in the water inlet; one end of the drive shaft is connected with the rotary wheel, and the other end penetrates through the turbine casing and is connected with a transmission device; and the turbine cover is buckled at the outer end of the turbine casing, and a turbine chamber is formed in the space of the turbine casing, the rotary wheel and the turbine cover; and the rotary wheel of the water turbine is cast by aluminum alloy, and the spray nozzle is made of a special plastic. The small-flow reel type irrigator water turbine is applicable to irrigation of a stadium, a golf course, a football field, a lawn, grassland, a park, a garden and various crops.