Abstract: Considering the construction defect of the embedded-ring foundation,a strengthening method based on circumferential prestressed technique is proposed in this paper.Taking an embedded-ring foundation of a wind turbine tower as an example,the numerical analyses are carried out to analyze the stress state of the concrete foundation with or without strengthening.The fatigue life of the concrete above the T-shaped plate is evaluated according to the relevant design codes and references.The results show that the strengthening method can effectively lower the fatigue stress amplitude of the concrete and raise the fatigue life of the concrete above the T-shaped plate.Furthermore,the stress level of the top surface of the foundation can be reduced and cracking phenomenon of the concrete can be improved.