In the context of increasingly fierce competition in the international construction market and gradually saturated Chinese domestic construction industry, regional construction industries urgently need to develop differentiated strategies to achieve sustainable development of international competitiveness. This research combines sustainability perspective with incremental perspective to propose the concept of sustainable international competitiveness and explores the impact of sustainability on the spatiotemporal evolution and influential factors of international competitiveness based on exploratory spatial data analysis and quantile regression method. Analysing panel statistical data from provincial regions in China, we find that most regions develop overseas construction projects independently, resulting in random distribution of competitiveness nationwide; meanwhile, spatiotemporal differentiation characteristics present geographical expansion of competitiveness decline in aggregation regions as well as robust polarization effect and path-dependent effect in dispersion regions. Additionally, determinant influential factors of sustainable international competitiveness vary with competitiveness increasing. These findings manifest unbalanced sustainability performances in strategy-driven and demand-driven regions resulting from single driving mode of competitiveness; reveal heterogeneous development mode of influential factors with inverted U-shaped effect, marginal effect, and escape-competition effect; and provide policy makers at national, regional, and firm levels with improvement strategies tailored to local conditions in extended industrial chain, integrated contracting mode, and updated strategy deployment; promoting high-quality and sustainable development of overseas construction projects with unified policy planning in the regional construction industry. •Evaluate international competitiveness by sustainability and incremental perspectives.•Dynamically mine spatiotemporal evolution characteristics of competitiveness.•Propose differentiated improvement strategies tailored to local conditions.