The rapid growth and high penetration of digitalization has caused profound changes in energy. This study investigates the impact of digitalization on energy and its mechanisms from an international perspective. The study demonstrates that digitalization reduces energy consumption, decreases energy intensity and optimizes energy structure. Comparatively speaking, digitalization has the most prominent impact on energy consumption and energy intensity. The mediating effect suggests that digitalization has a significant indirect impact on energy by promoting technological innovation, accelerating human capital accumulation and alleviating industrial structure distortions. We interestingly found that technological innovation has the strongest mediating effect in the impact of digitalization on energy consumption, human capital plays the most prominent mediating role in the impact of digitalization on energy intensity, and industrial structure distortion plays the strongest mediating role in the impact of digitalization on energy structure. Heterogeneity analysis indicate that digitalization has a greater impact on energy in low-income level countries and underdeveloped regions, and a smaller impact on energy in high-income level countries and developed regions. This study confirms the energy saving effects of digitalization at the international level, providing a policy reference for the world's energy transition.