Based on the stress-bubble fictitious soil-pile model and the improved hyperbolic model considering the initial critical frictional resistance of the pile-soil interface，a simplified method for calculating the settlement of vertically loaded single pile is proposed，which can consider the effect of stress diffusion at the pile tip and the initial critical frictional resistance at the pile-soil interface. Firstly，the influence degree of the model parameters on the settlement of a single pile is analyzed and discussed by using the present calculation method，and the reasonable value ranges of model parameters are given. Then，the rationality of the present calculation method is verified by comparing the results obtained using the present calculation method with the field measured data. Furthermore，the proportion of pile compression and pile tip soil settlement，the distribution law of pile axial force and the characteris? tics of pile lateral friction resistance under different pile top loads are further analyzed and studied. The present calculation method has clear parameters and simple application，which can provide a more accurate settlement value for pile foundation design，thus having a wide engineering application prospect.