A device for diagnosing a motor parameter, comprising a master chip, an excitation conditioning circuitry, a motor resolver unit, and a sine and cosine conditioning circuitry, wherein the master chip comprises a first analog-to-digital converter, a second analog-to-digital converter, a first processing unit, and a monitoring core; the first processing unit is configured to send an excitation signal to the motor resolver unit through the excitation conditioning circuitry; the motor resolver unit is configured to generate a sine analog signal and a cosine analog signal based on the excitation signal; the sine and cosine conditioning circuitry is configured to process the sine analog signal and then output the sine analog signal to the first analog-to-digital converter; the sine and cosine conditioning circuitry is further configured to process the cosine analog signal and then output the cosine analog signal to the second analog-to-digital converter; the first analog-to-digital converter is configured to convert a processed sine analog signal to a sine digital signal and to send the sine digital signal to the first processing unit and the monitoring core respectively; the second analog-to-digital converter is configured to convert a processed cosine analog signal to a cosine digital signal and to send the cosine digital signal to the first processing unit and the monitoring core respectively; the first processing unit is further configured to obtain a first motor angle based on the sine digital signal and the cosine digital signal and send the first motor angle to the monitoring core; the monitoring core is configured to diagnose the sine digital signal to detect whether or not the sine digital signal is abnormal; the monitoring core is further configured to diagnose the cosine digital signal to detect whether or not the cosine digital signal is abnormal; and the monitoring core is further configured to diagnose the first motor angle to detect whether or not the first motor angle is abnormal; wherein the monitoring core is further configured to obtain a third motor angle based on the sine digital signal and the cosine digital signal; and the first motor angle is diagnosed by the monitoring core to detect whether or not the first motor angle is abnormal by detecting, by the monitoring core, whether or not a difference between the first motor angle and the third motor angle falls within a range of an angle diagnosis threshold, and if not, determining that the first motor angle is abnormal. the first processing unit is configured to send an excitation signal to the motor resolver unit through the excitation conditioning circuitry; the motor resolver unit is configured to generate a sine analog signal and a cosine analog signal based on the excitation signal; the sine and cosine conditioning circuitry is configured to process the sine analog signal and then output the sine analog signal to the first analog-to-digital converter; the sine and cosine conditioning circuitry is further configured to process the cosine analog signal and then output the cosine analog signal to the second analog-to-digital converter; the first analog-to-digital converter is configured to convert a processed sine analog signal to a sine digital signal and to send the sine digital signal to the first processing unit and the monitoring core respectively; the second analog-to-digital converter is configured to convert a processed cosine analog signal to a cosine digital signal and to send the cosine digital signal to the first processing unit and the monitoring core respectively; the first processing unit is further configured to obtain a first motor angle based on the sine digital signal and the cosine digital signal and send the first motor angle to the monitoring core; the monitoring core is configured to diagnose the sine digital signal to detect whether or not the sine digital signal is abnormal; the monitoring core is further configured to diagnose the cosine digital signal to detect whether or not the cosine digital signal is abnormal; and the monitoring core is further configured to diagnose the first motor angle to detect whether or not the first motor angle is abnormal; wherein the monitoring core is further configured to obtain a third motor angle based on the sine digital signal and the cosine digital signal; and the first motor angle is diagnosed by the monitoring core to detect whether or not the first motor angle is abnormal by detecting, by the monitoring core, whether or not a difference between the first motor angle and the third motor angle falls within a range of an angle diagnosis threshold, and if not, determining that the first motor angle is abnormal.