Abstract: The present disclosure discloses an asymmetric wavelength multiplexing and demultiplexing chip based on inverse design, which belongs to the technical field of optical components, systems or instrument. The chip includes the first-level asymmetric wavelength multiplexing and demultiplexing unit and the second-level symmetric wavelength multiplexing and demultiplexing unit, which is constructed by silicon based photonics integration technology, includes a substrate, a bottom cladding layer, a core layer and a top cladding layer sequentially stacked from bottom to top. The functional regions inside the first-level unit and the second-level unit are designed based on the inverse design algorithms, and are composed of subunits on the submicron or nanometer scale.