Continuous-variable entangled optical fields are important quantum resources for realizing quantum computing, quantum communication and quantum precision measurement. Continuous-variable quantum systems have the advantages of deterministic generation, high-efficiency quantum detection, and excellent compatibility with classical communication systems. Quantum channel capacity is an important figure of merit in quantum communication. Multiplexing is useful in improving the quantum channel capacity, which is realized by combining multiple discrete values of a certain degree of freedom into a single channel, such as wavelength, polarization, and temporal mode. Orbital angular momentum multiplexing is an efficient wayto increase the channel capacity in quantum communication, since in principle the topological charge of orbital angular momentum can be arbitrary integers. Four-wave mixing process based on the double-Λ energy level structure of alkali metal atomic ensemble is an efficient way to prepare a spatially multi-mode entangled state with the advantages of naturally matching the atomic transition. It has been widely used in quantum state engineering, quantum precision measurement, quantum beam splitter, and so on. Recently, our group generates orbital angular momentum multiplexed continuous variable entangled state based on the four-wave mixing process in cesium atomic ensemble, and realized deterministic distribution of orbital angular momentum multiplexed quantum entanglement and quantum steering. In this paper, we experimentally demonstrate that the entanglement of EPR entangled state carrying l=1,?2 order topological charge is the same as that of l=0 order Gaussian mode. Furthermore, we characterize quantum correlation of optical fields carrying l=0,?1,?2 order orbital angular momentum in terms of Gaussian quantum discord and investigate its evolution in a lossy quantum channel. Our results show that Gaussian quantum correlation of orbital angular momentum multiplexed optical fields is robust in a lossy environment. Our results provide references for realizing high channel capacity quantum communication by using orbital angular momentum multiplexed continuous variable entangled state.