Disclosed herein is a signal processing system for medical imaging system using a multi threshold voltage. The signal processing system for medical imaging system may include: a signal detector detecting radiation emitted from radiopharmaceutical products injected into an object or radiation irradiated to the object and transmitting the object to generate and output a radiation detection signal an analog signal processor receiving radiation detection signals for each channel output from the signal detector and a plurality of preset different threshold voltages and each comparing the received radiation detection signals with signals depending on the plurality of different threshold voltages to generate and output a plurality of trigger signals and a digital signal processor receiving the trigger signals and acquiring energy information, time information, and position information representing detailed information on the radiation detection within the object on the basis of the received trigger signals.
