The Fo content of olivine is a key parameter for understanding the processes of lunar magmatic evolution. However, limited by detection methods, obtaining the Fo content of olivine on the lunar surface has long been confronted with numerous challenges. Traditional methods such as Electron Probe Microanalysis (EPMA) require polishing and sample preparation, making them unsuitable for future in-situ exploration missions. This study employed microscopic infrared spectroscopy, microscopic Raman spectroscopy, and Energy Dispersive Spectroscopy (EDS) to conduct compositional analysis on olivine grains in Chang'e-5 (CE-5) lunar soil samples. We verified the reliability of the infrared spectroscopy Reststrahlen Band (RB) characteristic peak position method and the Raman spectroscopy main peak shift method for the quantitative inversion of olivine Fo content by comparative analysis. Furthermore, the Fo contents derived from the three analytical techniques exhibit systematic deviations, reflecting differences in their respective technical principles and information depths. The low Fo contents suggest that the basalts at the CE-5 landing site have undergone intense crystallization differentiation, while the coexistence of olivines with distinct compositions may stem from magma mixing events. Not only does this study deepen the understanding of the magmatic history of CE-5 samples, but the spectroscopic methods validated herein also enable the systematic acquisition of olivine Fo contents on the lunar surface during the future Chang'e-7 mission, through a combination of orbiter-based infrared surveys and lander-based high-precision Raman detection, thereby providing a novel approach for in-depth studies of lunar magmatic evolution.