A receiving method for multi-cast packets includes the steps of creating a plurality of buffer partitions in a memory; for writing the received multi-cast packets that belong to a same data block into the same buffer partition in sequence; decompressing and combining all the multi-cast packets in the completely received buffer partition into the data block that the multi-cast packets belong to, writing the combined data block into a storage device, and emptying the completely received buffer partition, when the multi-cast packets that belong to the data block in any buffer partition are received completely; and transmitting a retransmission request to a transmitting end for any buffer partition that is not empty and in which the multi-cast packets that belong to the data block are not received completely.