Facing the dual crisis of global warming and energy shortage, China has clearly put forward the strategic goal of carbon peaking and carbon neutrality, and the Report of the 20th National Congress of the Communist Party of China emphasized the key role of green low-carbon industry and green low-carbon lifestyle in achieving high-quality development. In this context, discussing the energy consumption and carbon emissions in-depth of households, an important energy-consuming sector, is of great significance for exploring effective paths for household carbon emission reduction. This paper takes the indirect energy consumption, which accounts for the main energy consumption of households, as the research object. Based on the data of Chinese Family Panel Studies (CFPS), this paper applies the Consumer Lifestyle Approach to measure household indirect carbon emissions, and constructs a two-way fixed effect model to empirically analyze the impact of internet usage on household carbon emissions. On this basis, the mediation effect model and the Bootstrap method are jointly used to verify the effect path of internet usage on household indirect carbon emissions. Further, from the three different perspectives of household location, urban and rural categories, and income level, the paper discusses the heterogeneous impact of internet use on household indirect carbon emissions. The results are as follows: firstly, internet usage positively promotes household indirect carbon emissions, and shows the most significant increasing effect on enjoyment-oriented consumption carbon emissions and development-oriented consumption carbon emissions, while it has no significant effect on survival-oriented consumption carbon emissions. Secondly, internet usage shows a positive impact on household carbon emissions mainly through the mediating variable which is online shopping. Finally, the heterogeneity analysis indicates that: internet usage has a significant positive impact on household carbon emissions in the eastern, central and western regions, and the intensity of the effect decreased in turn from the central, the western to the eastern regions; the impact of internet usage on urban household carbon emissions is mainly composed of enjoyment-oriented and development-oriented consumption carbon emissions, and the impact on rural household carbon emissions is mainly composed of enjoyment-oriented and survival-oriented consumption carbon emissions; in terms of income level, the positive impact of internet usage on household indirect carbon emissions is mainly reflected in higher-income households, but the impact on middle-income and lower-income households is not significant. Therefore, in the process of internet accelerating development, try to promote the effective integration of low-carbon economy and internet development, strengthen the construction of internet connotation and ecological governance, guide the internet users to increase their awareness of environmental protection, and encourage households to shift their consumption to green patterns under the conditions of ensuring the improvement of residents’ living standards. In these ways, to lay a good micro-foundation for the realization of the carbon peaking and carbon neutrality goals.