To satisfy the requirements for active illumination， structural compactness， and high reliability of multispectral microscopic imaging instruments for deep-space exploration， this paper designs a ring-shaped multicolor LED active illumination source and develops a multispectral microscopic imaging system based on this source. In planetary surface exploration missions， microscopic imaging systems are expected to provide both fine spatial detail and spectral information for mineral identification and material analysis. However， conventional multispectral microscopic imaging devices often suffer from a relatively large volume， limited spectral channels， and complicated mechanical structures， which make them difficult to apply in deep-space payloads under strict constraints on size， weight， power consumption， and long-term operational stability. To address these problems， this study proposes a compact active illumination scheme with multiple spectral bands and no moving parts， aiming to improve system integration and applicability in future deep-space missions.The proposed illumination source adopts a dual-ring tilted array structure concentric with the imaging optical axis. By arranging the LEDs in two concentric tilted rings， the source provides illumination from multiple directions around the sample， which helps suppress directional shadows caused by microscopic surface topography and improves the uniformity and stability of the illumination field. This structural design is especially suitable for microscopic imaging of uneven sample surfaces， where local protrusions and depressions may significantly affect image quality under conventional directional illumination. At the same time， the overall radius of the designed light source is only 35 mm， which demonstrates a high level of miniaturization and makes the source suitable for compact payload integration.The light source integrates LEDs in 14 spectral bands covering the wavelength range from 400 to 1600 nm， enabling multispectral imaging from the visible region to the near-infrared region. Such spectral coverage provides the capability to capture both morphological and spectral characteristics of target samples and supports subsequent mineral discrimination and reflectance analysis. Considering the practical limitations of single-LED irradiance output and the restricted available space in the compact source structure， an enhancement strategy for relatively weak spectral bands is proposed. By increasing the number of LEDs or optimizing the arrangement for specific bands with insufficient irradiance， the illumination capability across different wavelengths is effectively balanced. This method improves the consistency of image acquisition conditions among multiple channels and enhances the overall usability of the multispectral system.Based on the designed illumination source， a complete multispectral microscopic imaging system is constructed. To verify its performance， spectral resolution and spatial resolution experiments are carried out. The experimental results show that the developed system can satisfy the basic detection requirements of multispectral microscopic imaging. In addition， mineral samples are selected as target objects for imaging experiments. Multispectral images are acquired in all 14 spectral bands and organized into a spectral data cube. On this basis， the reflectance spectra of the target minerals are reconstructed and compared with the corresponding measurements obtained using a spectrometer. The comparison results indicate that the reconstructed spectra are highly consistent with the spectrometer measurements in overall spectral profile and variation trend. This agreement demonstrates that the proposed system can effectively recover the spectral characteristics of the target samples and confirms the feasibility of using the ring-shaped multicolor LED illumination source in multispectral microscopic imaging applications.The results show that the proposed ring-shaped multicolor LED active illumination scheme has several advantages， including compact structure， no moving parts， high integration capability， and a relatively large number of spectral channels. It can effectively improve illumination performance under microscopic imaging conditions and support accurate multispectral image acquisition and spectral reconstruction. Therefore， the proposed design provides an effective technical solution for multispectral microscopic imaging payloads under the strict engineering constraints of deep-space exploration. It can also serve as a useful reference for the design， optimization， and system integration of illumination sources in future planetary surface exploration instruments.