In the field of industrial detection, the performance of long working distance microscope objectives is of crucial importance, especially in high precision and high resolution application scenarios. Traditional long working distance objectives are often limited by a small numerical aperture and a narrow spectral range, which restricts their application in some complex industrial inspection tasks.To overcome these limitations, this article proposes an innovative design scheme that is based on the typical structure of long working distance microscope objectives to optimize the initial structure and performance of the objective. Starting from the requirements of design parameters are based on the theories of third-order aberrations and first-order chromatic aberrations, combines the typical structure of existing long working distance microscope objectives and uses the analytical method to solve the initial structure of the long working distance and large numerical aperture microscope objective, and then optimizes the obtained initial structure. Through this design method, this article successfully designs and optimizes a 20×long working distance and wide wavelength range microscope objective. The design of this objective fully considers key parameters, including working distance, numerical aperture, distortion, and working wavelength range, to ensure its performance in practical applications. The working distance of the designed objective reaches 22.2 mm, the numerical aperture is 0.42, the distortion is controlled within 0.6%, and the working wavelength range is from 430 nm to 900 nm, covering a wide wavelength range from ultraviolet to near-infrared, making it adaptable to various inspection requirements. The lens design must achieve high imaging quality in simulation while complying with manufacturing constraints. The processing and assembly errors of various optical components during the manufacturing process are important factors affecting the overall precision. To ensure the compatibility of the objective with the tube lens system, this article also designs a matching tube lens. Through testing, the results show that this combination can provide high-quality images and meet the high standards of industrial inspection. In addition, to solve the possible deviations in the manufacturing and assembly process, this article also conducts core adjustment and mechanical structure design to ensure the stability and reliability of the objective's performance. The objective after centering can clearly observe the diffraction rings of the star point and they are standard circles, indicating that the objective has good imaging quality and no obvious spherical aberration or coma. The final performance test results show that the resolution of this microscope objective reaches 1 400 lp/mm under both green and white detection light sources, and the infrared defocus at 900 nm wavelength is only 2 μm. Based on the actual processing conditions, a tolerance analysis is conducted, mainly selecting the thickness deviation of the lens, the deviation of the curvature radius, and the eccentricity and tilt deviation between the lens groups as the research objects, and using the root mean square radius of the diffraction spot as the evaluation index, 500 times of Monte Carlo simulation analysis is carried out. The tolerance sensitive items mainly exist in the eccentricity and tilt of the three-lens cemented lens, and their change amounts are all below 5%, which can meet the actual manufacturing requirements.In addition, the designed objective not only has the advantage of long working distance but also has the characteristics of high resolution and wide spectral range, which has certain reference value for the design and manufacture of long working distance and large numerical aperture microscope objectives. With the increasing demand for industrial automation and precision manufacturing, the development of such high-performance objectives will help improve production efficiency and product quality, and further promote the development of industrial inspection technology to a higher level.