Recently, quantum communication has become a very popular research field. Quantum Key Distribution(QKD) plays an important role in the field of quantum communication, based on its unconditional security in terms of theory and feasibility in applications. Among all kinds of QKD protocols, QKD protocols resisting collective noise are widely studied. In this paper, an improved fault-tolerant QKD protocol resisting collective noise is proposed and a feasible plan for information reconciliation is presented. The proposed protocol’s qubit efficiency has achieved 28.57%, which is the best among all the fault-tolerant QKD protocols against collective noise, indicating that the proposed protocol can improve the transmission efficiency of quantum key distribution.