The invention discloses a flow meter detection device based on a volumetric method, and belongs to the technical field of meter detection. The measuring mechanism comprises an oil inlet
pipe, a flow meter body, an inflow
pipe, measuring tanks, an overflow mechanism, an outer sleeve, a
piston disc, an extending sleeve, a follow-up rod, a pressing block, a lateral sleeve, a transverse rod and a fixing mechanism, one end of the oil inlet
pipe is connected to the
oil tank, the other end of the oil inlet pipe is connected to the inflow pipe, the inflow pipe is connected to the side walls of the two measuring tanks, and the overflow mechanism is connected to the outer sleeve. The flow meter body is installed on an oil inlet pipe, the overflow mechanism is installed on an
oil tank, the outer sleeve is coaxially installed on a measuring tank, the influence of
gas pressure is avoided through the design of an air inlet hole, convenient manual control is provided through the combination of a follow-up rod and a pressing block, and the multi-stage positioning function is achieved through the cooperation of a lateral sleeve and a transverse rod. By means of the multi-structural design, the measurement accuracy and
repeatability of flow measurement are remarkably improved.