The invention discloses an abnormal state tracking and monitoring method for a primary circuit in a nuclear power plant and a system thereof. The method comprises the following steps: a temperature and pressure operation limit model of a primary circuit in the abnormal state is constructed according to operation characteristics and operation limit conditions of the primary circuit in the abnormalstate; according to the main pump operating state of the primary circuit, the state of accident operation procedures being executed and the P signal state, the corresponding temperature and pressure operation limit model of the primary circuit is selected; and the operating state of the primary circuit in the abnormal state is obtained, and the operation strategy of the primary circuit is adjustedin real time according to the selected temperature and pressure operation limit model of the primary circuit in the abnormal state. By combining the operation characteristics and operation limit conditions of the primary circuit in the abnormal state, the temperature and pressure operation limit model of the primary circuit in the abnormal state is constructed, which can assist an operator to conveniently and intuitively monitor the operating state of the primary circuit during the period of executing the accident operation procedures, timely adjust the appropriate operation strategy and steadily retreat to a safe state.