The rapid advancement of fluorescence microscopy technology has increased the need for better excitation light sources, particularly for multi⁃wavelength lasers coupled in single mode fiber. This article explores the technology of coupling multi⁃wavelength lasers into single mode fibers within the spectral range of 400-680 nm. To enhance the coupling efficiency of different wavelengths, a triplet lens is designed to effectively reduce chromatic aberration. Moreover, a fiber coupling component structure and a quick and easy coupling adjustment method was developed to address the challenges of fiber coupling alignment. Fiber coupling experiments involving four commonly used laser wavelengths in fluorescence microscopy (405, 488, 561, 638 nm) have demonstrated a coupling efficiency of over 65% for all four wavelengths. These results validate the effectiveness of the multi⁃wavelength lasers coupler designed in this study. Furthermore, due to its simple adjustment and low cost, the coupler holds significant commercial value and establishes a solid foundation for the localization of multi⁃wavelength lasers coupled in single mode fiber.