The utility model discloses a heavy current and constant current discharging device of a parallel type storage battery, which is characterized in that the device comprises one or more constant current discharging modules mutually connected in parallel; the discharging modules are connected with one another through communication lines; and each discharging module is connected with the storage battery. The discharging module achieves coarse adjustment or fine adjustment of discharged currents by controlling the filing number of fling-cut switches and regulating current set values sent to a direct current converter. The device has the advantages that the precision of current discharging control and regulation is high, the structure is simple, the parallel connection of the discharging modules of different capacities can be realized, and different current distribution modes, such as automatic modes, manual modes and the like, can be realized during parallel connection.