The pressure bearing capacity of fractured formation is narrow, lost circulation is more likely. In order to solve the problem of improving the pressure bearing capacity of fractured formation, the wellbore strengthening model was established, the key factors influencing the bearing capacity were analyzed, and a new cross-link plug technology was developed. Results show that the reasons of wellbore strengthening failure are sealing plug instability or fracture propagation. The pressure bearing capacity of fractured formation is determined by the bearing pressure of sealing plug and the fracture propagation pressure. To get high pressure bearing capacity, lost circulation materials demands high strength, high friction coefficient, high elastic deformation rate, low permeability, sealing plug position demands close to fracture mouth, and the sealing plug thickness need be moderate. The cross-linked plugging technique can significantly improve the positive bearing pressure and reversed bearing pressure of sealing plug. Experimental results show the positive bearing pressures can up to 20MPa, and the reversed bearing pressures are greater than 3MPa for 1-5 mm fractures. Field applications show that the model has good applicability, and it can be used to guide field applications effectively. The model provides a theoretical reference for wellbore strengthening in fractured formation.