The laboratory model test was conducted to analyze the influence of mud circulation time on the vertical bearing characteristic of bored pile in order to analyze the impact of mud cake and mud penetration layer on the vertical bearing characteristic of bored pile. A calculation formula for single pile settlement considering the mud cake and mud penetration layer was derived based on the principle of the shear displacement method, and the validity of the theory was verified through model test and numerical simulation. The influencing factor of mud penetration on bored pile was discussed. Results showed that the water mass fraction of the soil around the pile increased with the extension of mud circulation time. The pile top settlement, pile shaft axial force and pile end resistance of the test pile gradually increased as the mud circulation time increased under the premise of the same pile top load, while the pile shaft side friction resistance gradually decreased. The results of theoretical calculation accorded well with those of model test and numerical simulation, which confirmed the correctness of the theoretical formula. The pile top settlement and bearing capacity are negatively correlated with the plastic shear modulus of the mud cake and the mud penetration layer.