Abstract: There are insufficient quantitative analyses on the impact of pre-reinforcement on vertical bearing characteristics of soft soil foundations.Relying on a case of a reclamation project in Zhejiang Province, we studied the improvement of vertical bearing capacity, pile top settlement control and reduction of negative friction resistance of the pile foundation after pre-reinforcement to the soft soil foundation.The α method, API-2000 method and λ method were given for the quantitative calculation of ultimate lateral friction resistance of the pile.At the same time, the calculation formulas for ultimate end resistance of pile foundation and settlement of pile top were given.Finally, through typical engineering cases, vertical static load tests were carried out on the test piles in the original silt soil and the pre-reinforced foundation soil respectively, and their results were compared, verified and analysed.It is concluded that the vertical ultimate bearing capacity of the pile foundation calculated by the recommended code was more conservative than the field test, while the results calculated by the α method were closer to the field test values.Pre-reinforcing the soft soil foundation can effectively improve the vertical bearing capacity of the pile foundation.In the engineering case, the vertical ultimate bearing capacity was increased by 50%,and the pre-reinforcement was also effective for control of negative friction resistance and pile top settlement, which provides a reference for the construction of similar reinforcement projects in soft soil.