To solve the inter-chiplet deadlock and network connectivity problems caused by link failures in multi-chiplet network, an optimized packet retransmission mechanism for multi-chiplet network was proposed. By using the "message merging" function in the retransmission mechanism, the number of control packets and the network load was reduced; By using the "message forwarding" function and adopting the forwarding to neighbor strategy, the fault-tolerant cost of the inter-chiplet network link failure was reduced. And more balanced load of the intra-chiplet network was realized. The simulation results show that the proposed method can increase the saturation bandwidth by 12.5% - 25% with similar latency compared with the turn restriction strategy. Furthermore, it can increase the saturation bandwidth by up to 50% in case of link failures. "Message merging" can effectively reduce the number of control packets, thus reduce the overall load of the network. "Packet forwarding" has lower fault-tolerance cost and can achieve more balanced load of intra-chiplet network.