An electromagnetic water meter converter, comprising: an excitation circuit, comprising a first analogue switch configured to switch to a measurement mode or a self-calibration mode; a calibration circuit configured to measure induced voltage signals according to a plurality of preset flow rates; a measurement circuit configured to process each of the induced voltage signals corresponding to each of the preset flow rates and output a digital signal, the measurement circuit comprising a second analogue switch configured to switch the measurement mode or the self-calibration mode; and a main control module configured to control the first analogue switch and the second analogue switch to switch to the measurement mode or the self-calibration mode, and correct a correction coefficient according to the digital signals and a preset calibration algorithm, wherein when the first analogue switch switches to the self-calibration mode, the excitation circuit is connected to the calibration circuit, and when the second analogue switch switches to the self-calibration mode, the calibration circuit is connected to the measurement circuit characterized in that the calibration circuit comprises a precision instrument operation amplifier, a sampling resistor connected to an input end of the precision instrument operation amplifier, an adjustable voltage divider connected to an output end of the precision instrument operation amplifier, and a low-pass filter connected to the adjustable voltage divider; the precision instrument operation amplifier is configured to acquire and amplify a voltage between two ends of the sampling resistor and output an amplified voltage signal; the adjustable voltage divider is configured to divide the amplified voltage signal according to the plurality of preset flow rates and output voltage-divided voltage signals; and the low-pass filter is configured to filter out a high-frequency signal from the voltage-divided voltage signals to obtain the induced voltage signals. an excitation circuit, comprising a first analogue switch configured to switch to a measurement mode or a self-calibration mode; a calibration circuit configured to measure induced voltage signals according to a plurality of preset flow rates; a measurement circuit configured to process each of the induced voltage signals corresponding to each of the preset flow rates and output a digital signal, the measurement circuit comprising a second analogue switch configured to switch the measurement mode or the self-calibration mode; and a main control module configured to control the first analogue switch and the second analogue switch to switch to the measurement mode or the self-calibration mode, and correct a correction coefficient according to the digital signals and a preset calibration algorithm, wherein when the first analogue switch switches to the self-calibration mode, the excitation circuit is connected to the calibration circuit, and when the second analogue switch switches to the self-calibration mode, the calibration circuit is connected to the measurement circuit characterized in that the calibration circuit comprises a precision instrument operation amplifier, a sampling resistor connected to an input end of the precision instrument operation amplifier, an adjustable voltage divider connected to an output end of the precision instrument operation amplifier, and a low-pass filter connected to the adjustable voltage divider; the precision instrument operation amplifier is configured to acquire and amplify a voltage between two ends of the sampling resistor and output an amplified voltage signal; the adjustable voltage divider is configured to divide the amplified voltage signal according to the plurality of preset flow rates and output voltage-divided voltage signals; and the low-pass filter is configured to filter out a high-frequency signal from the voltage-divided voltage signals to obtain the induced voltage signals.