To analyse size effect of high-strength concrete column under small eccentric loading, experimental analysis was carried out on 3 categories of different sizes of high-strength concrete columns under small eccentric loading. The columns' section size was 200 mm × 200 mm, 400 mm × 400 mm and 800 mm × 800 mm, respectively. Failure mode, ultimate strength, deformation capacity and cross-sectional strain distributing rules were compared to get the size effect law. The results show that the compressive failure mode and cross-sectional strain distributing rules of HSC column under small eccentric loading are basically the same, and the size effect isn't obvious. Ultimate strength and deformation capacity of HSC column under small eccentric loading have size effect obviously. With increase of section size, safety reservation of ultimate strength is reduced and deformation capacity also reduces.