Abstract: The transformer is the key equipment of the power transformation and distribution station, and its operation status significantly affects the security and stability of the power grid. Insulating oil is an important working medium in the transformer, which plays an important role in insulation and heat dissipation during the transformer operation. Mineral insulating oil is the current widely used type of transformer insulating oil. The component characteristics of insulating oil have a significant impact on the working performance of the transformer. With the extension of operation time, the insulating oil is prone to oxidation and aging, resulting in the reduction of insulation reliability. Accurate analysis of the components of insulating oil and early detection of oxidation aging of insulating oil are of great significance to improve the operation safety level of the transformer. Mass spectrometry has shown good application potential in the analysis of insulating oil components, oxidation products and aging indicators. The research progress of mass spectrometry technology in insulating oil performance and quality detection, oxidation and aging product detection and process mechanism analysis in recent years are reviewed, and suggestions for further improving the accuracy of the performance and fault analysis of insulating oil in the future are put forward.