Based on the fictitious soil pile model, the effect of pile-end stress diffusion on the settlement of a single pile has been investigated theoretically. Firstly, a pile-end stress-bubble fictitious soil pile model considering the spread of the pile-end stress-bubble was proposed to simulate the supporting effect of the pile end soil on the pile body by combining the fictitious soil pile model and Boussinesq solution. Then, based on the load transfer method, an analytical solution of single pile settlement considering pile-end stress-bubble diffusion in layered foundation was derived by utilizing the double-broken-line model for the soil around the pile. Furthermore, the effects of parameters such as elastic limit displacement, elastic shear stiffness coefficient and additional stress value on the settlement of single pile were discussed based on the present solution. Finally, combining with the actual engineering data, the present method was validated by comparing with existing theoretical solution. The stress-bubble fictitious soil pile model is more meaningful for engineering applications on account of the obvious advantage that the stress diffusion boundary at pile end can be given more strictly.