An effective and economical DC fault current limiting method is a key technology in the construction and development of flexible DC transmission grid. Based on this, an economical flux-coupling DC fault current limiter (FCL) is proposed, which greatly reduces the number of power electronic devices used. Firstly, its working principle and mathematical model are analyzed, and the mathematical expression of branch current of FCL is analyzed. Secondly, the joint operation steps with the direct current circuit breaker (DCCB) are given, and the mathematical expression of DC current is analyzed in four stages. Finally, the correctness of the theoretical derivation results, the excellent performance of the proposed FCL in reducing electrical and thermal stress and its economical efficiency are verified in the MATLAB/ Simulink platform.