The low-carbon transformation of energy consumption is a key path to achieving the carbon emissions peak and carbon neutrality in China. Furthermore, technological innovation and policy regulation are necessary to promote low-carbon transformation of energy consumption, especially considering the issues associated with population aging. According to empirical facts and theoretical analysis, we demonstrate that population aging, technological innovation, and policy regulation affect the low-carbon transformation of energy consumption. Then, we build a PVAR model and conduct an empirical test using provincial panel data in China from 2003 to 2020. The results show that population aging, technological innovation, and policy regulation all contribute to the low-carbon index of energy consumption, and the interaction among the three forms a transmission mechanism to promote the low-carbon transformation of energy use in terms of both the production and consumption. The positive effect of population aging on the low-carbon index of energy consumption exhibits an inverted U-shaped curve that gradually increases at first and then gradually decreases. The positive effect of policy regulations on the low-carbon index of energy consumption follows an L-shaped curve, and the positive effect of technological innovation on the low-carbon index of energy consumption shows a constantly increasing trend. From the perspective of impact intensity, compared with population aging and policy regulation, technological innovation has a higher impact on the low-carbon index of energy consumption. With the rise in population aging, the effects of technological innovation, policy regulation, and technological innovation-policy regulation on the low-carbon index of energy consumption are ranked from low to high intensity. From the perspective of regional heterogeneity, compared with the middle and western regions, the positive effect of technological innovation and policy regulation on the low-carbon index of energy consumption under population aging in the eastern region is more significant. Our findings reveal the value of technological innovation and policy regulation in promoting low-carbon transformation of energy consumption while population aging is increasing in all countries around the world.