The proposed Laguerre Gaussian mode and orbital angular momentum beam demultiplexing hybrid using multiplane light conversion simultaneously achieved mode demultiplexing and 90° hybrid , with good performance and wavelength characteristics. The designed and implemented Laguerre Gaussian mode demultiplexing hybrid using multiplane light conversion achieved good performance and a feasible scheme, thereby providing a technical reference for designing mode multiplexing and demultiplexing in space division multiplexing technology.