The invention relates to the technical field of network communication in a nuclear industry and provides a double-loop network bit error rate test method. According to the test method, an original data packet for a test and a test starting or ending signal are generated through a computer. The method comprises the steps of obtaining the original data packet for the test and the test starting or ending signal generated by the computer and storing original data; if the obtained signal is the test starting signal, sending the original data packet to at least two adjacent network nodes adjacent to a tested network, wherein a reverse double-loop network is formed between the at least two adjacent network nodes; after the original data packet passes the at least two adjacent network nodes along two different directions in the reverse double-loop network, generating a target test data packet; and receiving the target test data packet and judging a bit error rate of the reverse double-loop network according to a comparison result of the original data packet and the target test data packet. The problem of testing the bit error rate of the reverse double-loop network can be solved.