The invention provides a high-voltage-level voltage qualification rate monitoring method and device. According to the method, data recorded in a power grid operation monitoring system and scene recording equipment are utilized to perform assessment type determination of a bus voltage measured by each measurement point, for different assessment types, different constraint thresholds are set, so that the voltage qualification rate of a plant station where the measurement point is located is automatically calculated, and the problem of relatively large calculation result error caused by calculation of the qualification rate by utilizing the voltage containing abnormal data in the prior art is solved.