Conventional energy sources are neither secure nor sustainable, which is the motivation behind the energy transition to expand the availability of renewables or nuclear energy. Such reform should remove social barriers to understanding the sustainable attitudes and corresponding influences of the public, especially from the younger generation’s perspective, as they will be the ethical consumers of the coming decades. The objectives of this study were to comprehend and compare British and Chinese undergraduates’ sustainable attitudes, the future vision of the energy transition, and corresponding influences. 94 and 98 questionnaires from the Britain and Chinese participants were collected respectively, including psychosocial and socio-economic factors as independent variables, and behavioural intention as the dependent variable. Participants' sustainable attitudes were comprehended via quantifying their psychosocial variables including awareness of climate change and energy sources, and their behavioural intentions, i.e. willingness to pay a financial premium for renewables and nuclear power. The collected socio-economic information included grade, gender, nationality and economic dependence. The differences between sustainable attitudes were analysed through one-way analysis of variance, and correlations between the independent and dependent variables were examined via a linear regression test. The results showed that participants in both countries demonstrated high climate change awareness and limited energy-related knowledge base, but still exhibited a higher acceptance of renewables than nuclear power, with 'energy security beliefs' and ‘energy sources familiarity’ being vital influencing factors. This phenomenon underlines the significance of unbiased education, especially regarding nuclear power. In addition, Britain participants expressed a greater willingness to pay extra for both energy sources than the Chinese, although this was not statistically significant. The differences can be explained by the varied cultural and historical backgrounds, socio-economic levels, political situations and energy systems of the two countries. Comparative studies in other countries are still in demand to enhance the comprehension of their inhabitants’ sustainable attitudes and to contribute to eliminating social barriers of the energy transition across the globe.