The invention provides an error checking method for a capacitive voltage divider. Error checking of the capacitive voltage divider is achieved by measuring a ratio error and an angular difference of the capacitive voltage divider. The error checking method is characterized by comprising the specific steps: converting a detected high voltage into a first low voltage (U1) suitable for data collection from a standard voltage mutual inductor, converting a voltage divided by the detected capacitive voltage divider (4) into a second low voltage (U2) suitable for data collection, sending the first low voltage (U1) and the second low voltage (U2) into a signal processing circuit at the same time to conduct analog and digital signal processing, obtaining the ratio error and the angular difference, and completing the error checking. The invention further discloses an error checking system and application of the error checking system in an electronic-type mutual inductor. The method and system can measure the ratio error and the angular difference of the capacitive voltage divider and have the traceability, and the measuring result is high in credibility.