Micro-LED, renowned for its exceptional brightness, energy efficiency, and rapid response times, has shown immense potential in the display technology sector, particularly in light of the ongoing advancements within the semiconductor industry. The detection of defects in the wafer is a crucial step in the production of Micro-LED, as it guarantees the dependability and excellence of the final product. The core technology underpinning the wafer defects detection system, which is microscopic visual online inspection, aids in the stable detection of product defects. Regrettably, the limitations in spectral range, field of view, and spatial resolution of current commercial microscopic objectives present a significant challenge in meeting the stringent high-precision and rapid detection demands for Micro-LED wafer defects. Based on our analysis of the system's operational requirements, the microscopic objective for the automatic optical inspection system intended for detecting defects in Micro-LED wafer must encompass a wide spectral range, offer a large field of view, achieve high spatial resolution, and maintain a considerable working distance. We established the design specifications and selected the camera based on the resolution and field of view criteria of the microscopic objective, aligning with international standards for microscopic objective. Considering the design priorities of a large field of view and a long working distance, the microscopic objective is structured as a retro-telecentric system, comprising three optical groups with positive, positive, and negative focal lengths for the front, middle, and rear groups, respectively. The angle ratios between the optical groups were established as Δu₁: Δu₂: Δu₃=0.8∶ 0.7∶ -0.5, in order to minimize the considerable light deviation between lenses and to ease the structural design and adjustment. Utilizing the multi-group combination calculation formula, we calculated the focal lengths of the optical groups to be φ₁=0.025 mm^-1, φ₂=0.020 mm^-1, and φ₃=-0.017 mm^-1. Considering that the front group introduces a Schmidt surface to reduce spherical and coma aberrations while avoiding excessive field curvature and astigmatism; the middle group uses single lenses and cemented lenses, with the cemented lenses incorporating anomalous dispersion glass to eliminate chromatic aberrations and secondary spectra, and a meniscus lens to correct field curvature while also compensating for the spherical and coma aberrations introduced by the front group; the rear group uses a combination of positive and negative cemented lenses to further compensate for the field curvature, coma and astigmatism introduced by the front and middle groups, and other off-axis aberrations. The coordinated interaction of the front, middle and rear groups achieves the correction and balance of aberrations. Based on the focal power distribution and the characteristics of the components in each optical group, we designed the initial optical system. We then used Zemax to perform preliminary optimization on the system to ensure that the first-order performance metrics met the design specifications. However, due to the influence of secondary spectra, MTF values across different fields of view were rather modest and did not reach the diffraction limit when accounting for wide-spectrum chromatic aberration correction. To address this, we employed the Buchdahl dispersion model, which converges faster than the standard Sellmeier and Schott models, to investigate the dispersion properties of glass. Dispersion coefficients of CDGM glass were computed using Matlab. The dispersion vector sum G₀ was utilized to assess the level of chromatic aberration correction in the optical system. Ray tracing of the initial optical system was used to determine the modulus of the dispersion vector sum of the initial structure, which guided the replacement of glass materials and achieved chromatic aberration correction in the initial optical system design. Ultimately, we developed a wide-spectrum, large-field microscopic objective composed of 11 easily manufactured, high-frequency glass components. It has a spectral range of 420 nm to 1 064 nm, a field of view on the object side of 3.3 mm, a focal length of 20 mm, a numerical aperture of 0.34, a working distance of 8 mm, a resolution of 0.88 μm in the visible light band and a resolution of 1.35 μm in the near-infrared band. A performance comparison with five typical 10× microscopic objectives from companies such as Mitutoyo and Olympus reveals that the developed wide-spectrum, large-field of view objective offers significant benefits in spectral breadth, imaging field of view, and numerical aperture. Image quality evaluation results indicate that the microscope objective corrects chromatic aberration over the entire spectral range and has a flat field of view with overall image quality near the diffraction limit. The tolerance study confirms that the objective meets both image quality and manufacturing standards for microscope objectives. This microscopic objective covers the spectrum from the visible light band to the near-infrared band, and with its large field of view and high-resolution imaging capabilities, it can effectively enhance the detection accuracy and efficiency of surface and subsurface defects in Micro-LED wafers.