In the present invention, provided are a magnetic resonance imaging system, a method for determining a SAR value of a magnetic resonance imaging system, and a computer-readable storage medium. The system comprises a radio-frequency transmitting coil, configured to receive radio-frequency power from a radio-frequency transmitting link and transmit radio-frequency power required for imaging to a scanned object. The system further comprises a reflection coefficient determining module, a resistance value determining module, and a SAR value determining module. The reflection coefficient determining module is configured to acquire a frequency response of a first input reflection coefficient of the radio-frequency transmitting coil when having no load and a frequency response of a second input reflection coefficient thereof when having the scanned object. The resistance value determining module is configured to determine a resistance value of the radio-frequency transmitting coil on the basis of the frequency response of the first input reflection coefficient, and determine a parallel resistance value of the radio-frequency transmitting coil and the scanned object on the basis of the frequency response of the second input reflection coefficient. The SAR value determining module is configured to calculate a SAR value of the scanned object on the basis of the resistance value of the radio-frequency transmitting coil and the parallel resistance value.