Design and on-orbit verification of Tianwen-1 multispectral camera

China's first Mars exploration mission Tianwen-1 was successfully launched on July 23, 2020. The multispectral camera is an essential payload of Tianwen-1 and is installed on the mast of the Zhurong rover. The scientific goals of the mission are to obtain multispectral images of the landing and inspection zones, investigate the surface material composition on Mars, and obtain basic information on the chemical evolution of Mars. This article introduces the scheme and design results of the Tianwen-1 multispectral camera. To improve reliability, Tianwen-1 realizes multispectral imaging and corrects axial chromatic aberration by switching eight narrow-band filters with different thicknesses, and achieves focusing function by switching six focus compensation lenses of different thicknesses. The scientific data of on-orbit work shows that the image is clear and the spectral data are normal. The spectral reflectance data of the calibration board taken by the multispectral camera on Mars are consistent with the ground measurement data. The spectral reflectance data of the Martian surface obtained by the multispectral camera are basically consistent with the spectral reflectance data obtained by the Mars Reconnaissance Orbiter Imaging Spectrometer (CRISM) in orbit.