Optical beam can carry both spin angular momentum and orbital angular momentum. Since its concept was proposed by Allen et?al in 1992, optical orbital angular momentum has attracted more and more interests. Optical orbital angular momentum has the characteristics of infinite bandwidth and orthogonal modes, which makes it a promising technology to transmit information. Firstly, the basic concept of optical orbital angular momentum is summarized. And then the generation of orbital-angular-momentum multiplexed entanglement source based on four-wave mixing process in continuous variable system is mainly reviewed, including the deterministic generation of 13 pairs of multiplexed continuous variable entanglement, the implementation of 9 sets of orbital-angular-momentum multiplexed tripartite entanglement and the realization of large-scale quantum network over 66 orbital angular momentum optical modes. Furthermore, the latest application of optical orbital angular momentum multiplexing entanglement source is also introduced, including the realization of 9 channels of all-optical quantum teleportation by utilizing the orbital-angular-momentum multiplexed continuous variable entanglement and the experimental implementation of the orbital-angular-momentum multiplexed quantum dense coding.