Abstract: At present, the last breaker protection for converter has the problems of poor reliability, complex logic or insufficient early warning, and there is an undesired tripping event of the last breaker protection for converter in practical project. Therefore,the realization strategy of last breaker protection in practical project is firstly sorted out. Based on the analysis of current loop characteristics of last breakers for converter in the paper, the current network of virtual AC line and virtual bus are constructed.Then, an algorithm of last breaker protection for converter is proposed based on the virtual current networks, which can solve the problem of identifying the last breaker for converter in principle. The proposed algorithm is compared with the algorithm used in practical engineering application, and the results demonstrate that the proposed algorithm can correctly identify the last breakers with clear and reliable principle, and avoid the problems of complex logic and the demand of traversing all working conditions.