To investigate the effects of various factors on the bearing capacity characteristics of Aeolian sand rigid long-short pile composite foundations, ABAQUS software was utilized to quantitatively analyze the impacts of pile length, pile elastic modulus, cushion layer thickness, and cushion layer elastic modulus under both collapsible and non-collapsible conditions in collapsible loess soil regions. The physical and mechanical properties of the collapsible loess soil were adjusted to simulate the collapsible condition, allowing for an exploration of the mechanical behavior and key parameter evolution under this state. The results indicate that advancing the pile length reduces settlement but significantly increases the maximum pile axial force. Specifically, when the pile length is increased from 0.5 m to 0.6 m, the maximum pile axial force increases by 34.29%. Changes in pile elastic modulus produce a negligible effect on settlement. An increase in cushion layer thickness reduces settlement. However, an excessively thick cushion layer may result in excessive loads on the soil between piles, potentially leading to plastic failure. Increasing the cushion layer elastic modulus to 24 MPa effectively reduces settlement, but a modulus that is overly high may cause stress concentration. Therefore, comprehensive consideration is needed in practical applications. The research results provide new references for the design and research of collapsible loess soil foundations.