In-situ composition analytical method of single fluid inclusion has the characteristics of in-situ, micro-area and non-destructive, which makes it an effective measure for geological fluid research. Compared with population composition analytical method, this method can avoid the mixed result of different period inclusions. Microscopic laser Raman spectra method and microscopic Fourier transform infrared spectroscopy method are two frequently used in-situ composition analytical methods of single fluid inclusion. This research introduced the experimental principles of these two methods, and discussed their test data and geological applications. The results show that the above two methods can be used to analyze the fluid properties of metallogenic processes, identify oil and gas evolution processes in oil and gas basins, restore formation/reservoir pressure, judge oil and gas maturity, etc. In conclusion, microscopic laser Raman spectra method and microscopic Fourier transform infrared spectroscopy method both enjoy wide application prospect.