Abstract: At present, the exploration and development of global oil and gas are accelerating from shallow conventional reservoirs to "depleted, deep, low-permeability, unconventional" fields, Oil-based drilling fluid is facing severe challenges of bottom hole overflow. In this paper, the countermeasure of wellbore strengthening of oil-based drilling fluid is put forward, which is "predicting fracture opening value-optimizing the types of wellbore strengthening materials-optimizing particle gradation and content-wellbore strengthening effect of indoor evaluating-precise managed pressure drilling on site". Based on this, this paper introduces and summarizes the new theories of "strong force chain frame network plugging loss channel, chemical consolidation strengthening rock mass structure, chemical film forming blocking fluid invasion", the new methods of "rock strength prediction based on digital twin model, drilling fluid filtration test for simulating nano-micron pores and fractures, pore-fracture-permeability analysis using multi-scale CT imaging technology, and mathematical model quantification of wellbore stress considering multi-field coupling of discontinuous media" and new materials corresponding to the new theories formed since the 21st century. Finally, the research direction of oil-based drilling fluid wellbore strengthening technology is prospected. In the future, real-time field data and deep learning algorithms can be combined to optimize and improve the simulation accuracy of the digital twin model of core and wellbore and the mathematical model of wellbore strengthening with complex fracture system. The micro-nano 3D printing technology can be used to design and manufacture the nano-micron pore-fracture filtration medium that can truly simulate the formation conditions. The preparation process can be optimized to obtain cheap, efficient and environment-friendly wellbore strengthening materials. The influence of material parameters on the wellbore strengthening effect can be finely characterized from the mesoscopic and microscopic perspectives. The wellbore strengthening database can be established and improved to facilitate the design of material particle gradation. With the continuous improvement of oil-based drilling fluid wall strengthening technology, it is expected to become the main mean of fast, safe and efficient drilling in domestic complex formation.