The invention discloses a phased overcurrent protection method and system for a multi-terminal flexible direct-current system. The method includes: judging whether fault occurs or not according to collected current data; when the fault occurs, determining whether actions occur in the overcurrent protection phase or not according to the current data and preset overcurrent protection setting value,and shutting overcurrent protection with no actions; when the fault is removed, unlocking all the shut overcurrent protection phases. The phased overcurrent protection method and system has the advantages of high selectivity and fast action speed, and demands of future multi-terminal flexible direct-current grid construction can be met.