To study the axial compression performance of H-shaped composite short columns with concrete-filled rectangular steel tubular flanges and double cellular webs, 19 full-scale specimens were designed with control parameters including slenderness ratio, confinement effect coefficient, steel yield strength, concrete axial compressive strength, hole-height ratio, and spacing-height ratio. Based on simplified steel constitutive models and constrained concrete nonlinear constitutive models, numerical simulations of 12 H-shaped cellular composite columns with concrete-filled rectangular steel tubular flanges were conducted using ABAQUS finite element software to obtain load-displacement curves of specimens. Through comparison with existing experimental data, the applicability and accuracy of the adop-ted material constitutive models and finite element modeling results were verified. Further parametric analyses were performed to investigate the influence of different parameter variations on the axial bearing capacity of this new type of short columns, thereby revealing the mechanical processes, failure modes, and load-bearing mechanisms. The results indicated that the bearing capacity significantly increased with the confinement effect coefficient, steel yield strength, concrete axial compressive strength, and spacing-height ratio but decreased with the slenderness ratio and hole-height ratio. All specimens exhi-bited similar failure patterns: outward bulging of flanges with convex failure morphology, and cellular steel webs developing cracks extending bilaterally along the web plane from circular holes. Finally, statistical regression analysis based on the 1stOpt software was conducted to establish a bearing capacity formula for this composite short column type, providing theoretical basis for practical engineering applications.