The invention discloses a harmonic suppression type signal processing system used for an electrolytic-tank anode current measuring device. The harmonic suppression type signal processing system is characterized by mainly comprising a processing chip U, a signal acquisition device JS, a triode VT4, a polarity capacitor C11, a diode D8, a phase-locked loop circuit serially connected between a COMP pin and a CS pin of the processing chip U, a second-order low-pass filtering circuit connected with the signal acquisition device JS, an emitter coupling logic circuit serially connected between the second-order low-pass filtering circuit and the processing chip U, a signal conditioning circuit serially connected between the emitter coupling logic circuit and an IN pin of the processing chip U, and a linear isolating circuit connected with an OUT pin, a G pin and a CLK pin of the processing chip U. The harmonic suppression type signal processing system has the advantages of reasonable design, simple overall structure and good using effect, and can ensure accurate measurement of the current of an anode rod of the electrolytic-tank anode current measuring device.