In order to resolve the problem of data packets losing abruptly in opportunistic networks, a fault-tolerant transfer algorithm based on interweaving code is proposed. The algorithm includes two parts: one is used by nodes sending data and another is used by receiving nodes to recover lost data. When the packets are sent, interweaving idea is used to disperse the packets. When the packets are received, interpolation method is used to recover the sequence of lost packets based on the strong autocorrelation of transferred packet. Then, interpolation method is used to recover lost data.