A dam seepage discharge high-accuracy flow meter with a measurement circuit comprises a container formed by a soleplate, a casing and a cover plate, a plurality of support bars arranged on the surroundings of the container soleplate, a motor arranged on the container, a liquid level switch arranged in the container, a water inlet pipe inserted into an open slot on the upper part of the container casing, a rotating bar connected with a water inlet of the water inlet pipe and an output shaft of the motor and a drainpipe equipped with a drain valve and connected with an outfall on the container soleplate. The flow meter of the invention has the advantages of simple structure, convenient use, high automation, concise and scientific measuring principle, large range ratio scope and high measuring accuracy. The fluid is measured at any time and flows away immediately without creating the problem of dirt deposition to affect measurement accuracy; therefore, the flow meter is particularly suitable for chronically and reliably operating seepage discharge monitoring work in the monitoring environments with small seepage discharge and impurities in a dam.