The reliability of solder joints is one of the key concerns in electronic packaging. Underfill was employed to match the thermal expansion coefficient between the substrate and the IC chip in electronic packaging, thereby protecting the solder joints and improving the reliability of the solder joints. However, the reliability of solder bumped flip chip will be affected by the changes in performance of underfill during the aging process. Therefore, the effects of several aging treatments on the thermo-mechanical properties and adhesion of underfill were studied in this paper. The thermo-mechanical properties of the underfill have the most obvious changes after hydrothermal aging treatment and high-temperature storage life treatment. There is no obvious similarity on organic interface and the inorganic interface for adhesion of underfill. High temperature storage has the most obvious effect on the adhesion of inorganic interfaces, while hydrothermal aging has the most obvious effect on the organic interfaces.