To achieve comprehensive real-time monitoring and forecasting of Martian dust storms, this study addresses the technical challenges posed by the Mars Color Imager (MARCI) aboard NASA's Mars Reconnaissance Orbiter (MRO), particularly its intricate spectral separation architecture and stringent manufacturing/alignment requirements, along with the limitations of China's Tianwen-1 Moderate Resolution Imaging Camera (MoRIC) regarding constrained field-of-view and narrow spectral coverage. We present a novel wide-angle multispectral imaging system designed for subsequent Mars exploration missions. The optical configuration comprises nine spherical lenses, achieving 130° cross-track and 30° along-track fields of view. It operates across a 260~750 nm spectral range with F/11 aperture, 13 mm focal length, 68 mm maximum clear aperture, and 185 mm total length-all meeting design specifications. This design employs a typical reverse magnification structure, utilizing the principal ray tracing formula and the reverse magnification front and rear group chromatic aberration balance relationship. Common ultraviolet optical crystals are incorporated to achieve wide-angle achromatic imaging. After optimizing the optical system, the maximum RMS radius of the spot diagram across the entire field of view does not exceed 10.3 micrometers. The Modulation Transfer Function (MTF) value at the cutoff frequency of 46 line pairs per millimeter across the full field of view exceeds 0.46, indicating excellent imaging quality. Additionally, the relative illuminance on the image plane remains above 74% across the entire field of view, fulfilling the design requirements. Given that the system incorporates three sapphire uniaxial crystals, which may lead to birefringence, CODE V was utilized to simulate two groups of o-light and e-light propagating through the optical system. Light tracing was conducted and analyzed for both groups, revealing that birefringence significantly impacts the optical system's performance. Based on the above, a composite filter integrating both polarization and spectral filtering has been designed. This enables the system to perform multispectral imaging across six spectral bands within the wavelength range of 260 nm to 750 nm, while eliminating the influence of birefringence on the optical system. Moreover, the tolerance analysis reveals that over 90% of the products achieve an MTF value of 0.3 or above at the cutoff frequency of 46 lp/mm across the full field of view, indicating excellent engineering feasibility. Lastly, thermal analysis of the system confirms that within the operational temperature range of -40 °C to 50 °C, the image plane displacement within the depth of field and MTF degradation remain insignificant, showcasing good thermal stability. In summary, the system possesses considerable practical worth and offers an invaluable reference point for the design of subsequent Mars sandstorm detection optical systems.