The invention belongs to the field of metal electrochemical corrosion testing, in order to solve the problems in the prior art that microorganisms cannot be aggregated and grown on the metal surface in a short period of time and the real-time electrochemical corrosion measurement of metal materials under the flow system cannot be carried out, and at the same time, the production of special working electrodes is omitted. Steps and cost, enhanced practicability, the present invention, the electrochemical test device of metal microbial corrosion under the flowing system, comprises cylindrical glass cavity, upper end polytetrafluoroethylene sealing cover, lower end polytetrafluoroethylene sealing cover, reference electrode, Salt bridge, auxiliary electrode, platinum sheet, dosing hole, sampling hole, working electrode, working electrode contact hole, working electrode contact, copper disc, screw, water inlet, water outlet, the cylindrical glass cavity is the main body of the device, and the hollow The upper and lower ends of the cavity are sealed with polytetrafluoroethylene. The upper end is equipped with a reference electrode, auxiliary electrode, dosing hole and sampling hole, and the lower end is equipped with a working electrode. The invention is mainly applied to metal electrochemical corrosion test occasions.