In MEMS laser tracking and aiming systems, MEMS micro-mirrors are identified as the key components. These micro-mirrors enable the systems to achieve stable tracking and aiming of targets through their control of laser deflection and the signal acquisition by photoelectric detectors. However, the pursuit of higher response speeds and sizes of larger mirror in the design process has led to a compromise in the scanning field of view, which does not meet the requirements for large field of view tracking and aiming of targets. To address the issue of the limited scanning field of view of MEMS micro-mirrors, this paper has conducted research on the wide-angle optics and has designed a wide-angle lens suitable for tracking and aiming systems.Utilizing Zemax optical simulation software, a wide-angle lens was designed, which composed of a bi-convex lens and two bi-concave lenses along with its mounting sleeve and clamp rings (Fig.6). The wide-angle lens was evaluated using indicators such as the beam divergence angle and the Gaussian fitting error of the light intensity distribution. A beam quality analyzer was employed to compare the beam quality before and after expansion, thereby analyzing the impact of the expanded field of view lens on the beam quality. An experimental characterization device was set up to characterize the expansion magnification rate of the wide-angle lens (Fig.8). By altering the control current of the voice coil motor's fast reflection mirror, the laser deflection angle before and after the addition of the wide-angle lens was compared to analyze the expansion results. A MEMS quasi-static micro-mirror was used to control the deflection of a 638 nm laser, and a practical application demonstration device was set up to compare the laser scanning patterns before and after expansion (Fig.9). This included line scanning patterns and Lissajous scanning patterns.The experimental results indicate that the designed wide-angle lens possess an expansion magnification rate of approximately 2.88 times, with the expansion nonlinearity error being less than 0.7% (Fig.14). There is no significant change in the laser beam quality before and after expansion, with the Gaussian fitting goodness exceeding 99%. The divergence full angle after expansion is controlled within 2 milliradians (Tab.4), ensuring the quality of the laser beam post-expansion. The use of the wide-angle lens has increased the scanning field of view of the original MEMS micro-mirror from less than 4° to over 10°, essentially meeting the design requirements.A wide-angle lens for MEMS micro-mirror laser tracking and aiming systems has been designed, characterized by its simple structure and stable expansion. With an expansion magnification rate of approximately 2.88 times and a nonlinearity error of less than 0.7%, the design of the wide-angle optics for MEMS micro-mirror laser tracking and aiming has realized a larger scanning field of view for the system. This has been successfully applied to the expanded scanning of MEMS micro-mirrors, contributing to the rational application of high-performance MEMS micro-mirrors with small scanning angles in laser tracking and aiming.