Orbital angular momentum(OAM) communication requires the alignment of the transmitting and receiving antennas, which limits the application scenarios of OAM communication. In this letter, we propose an OAM mode modulation-based wireless backhaul communication scheme for the downlink in a broadcast network. According to the principle of superposition of electric fields, this scheme generates multiple OAM modes simultaneously through uniform circular array(UCA) for information modulation and radiates signals to the outside in a periodic cyclic excitation manner. This scheme does not require the alignment of transmitting and receiving antennas, and the deployment of the receiving antenna position can be very flexible. Compared with QAM modulation, OAM mode modulation has strong anti-interference performance. Meanwhile, as the modulation order increases, the bit error rate(BER) will not change significantly.