Background <p>Enough supply of physicians plays a vital role in ensuring equitable access to healthcare for residents. This study aims to present a national profile of physician supply and investigate its correlation with all-cause mortality in China.</p> Methods <p>This epidemiological study utilized population-level administrative data. The estimated annual percentage change (EAPC) was calculated to evaluate temporal trends in physician density. The concentration index (CCI) was used to analyze inequalities in physician supply. A generalized estimating equation model and restricted cubic spline were employed to explore the association between physician supply and mortality.</p> Results <p>In China, physician density increased significantly from 23.13 per 10,000 population in 2016 to 30.40 per 10,000 population in 2021, which corresponds to a substantial growth of 23.92% with an EAPC of 5.79% (95% CI: 4.89–6.69). Concurrently, age-standardized all-cause mortality has exhibited a declining trend. The CCI for physician supply remained stable at approximately 0.327. Furthermore, a multivariable generalized estimating equation model and restricted cubic spline analysis demonstrated a strong negative correlation between physician supply and all-cause mortality (R² = -0.923, P &lt; 0.001). Compared to regions with high physician density, the risk ratios were 1.17 (95% CI: 1.07–1.29) for regions with low physician density, 1.16 (95% CI: 1.07–1.26) for those with lower middle density, and 1.06 (95% CI: 1.00–1.13) for those with upper middle density.</p> Conclusions <p>Regional disparities in physician supply continue to exist, with a gradual narrowing gap within regions. Higher physician supply is associated with reduced all-cause mortality, underscoring the critical importance of equitable physician distribution.</p>