The invention relates to a turning point calculation model and a breaker state monitoring method and system for a motor current. The method comprises the steps that firstly, a hall current sensor is used for collecting current signals of a vacuum breaker energy storage motor; secondly, two peak values on a motor current-time curve are found out; thirdly, a turning point on the current-time curve is solved based on the second step through a turning point calculation method; fourthly, the turning point is obtained based on the third step, the obtained turning point is compared with a set threshold value, and if the turning point exceeds a set threshold value deviation range, failure warning is carried out. The method has high precision and reliability, and real-time monitoring of the working state of the breaker can be effectively achieved.