Wellbore integrity is a key factor to ensuring the safe and sustainable operation of oil and gas wells throughout the life cycle. As the global energy exploitation expands to regions with deep formations，deep seas and complex geological conditions，the wellbore barrier system is facing unprecedented challenges due to extreme conditions such as high temperature and high pressure （HTHP），high stresses and corrosive media. Over recent years，great progress has been made in research on wellbore integrity thanks to the development of new materials，applications of intelligent monitoring techniques and innovation of risk assessment models. This paper summarizes the research status of multiple aspects of wellbore integrity，such as HTHP-tolerant materials，composite materials resistant to hydrogen penetration，smart sensors and data-driven prediction models，and multi-factor risk assessment methods. Moreover，it reviews the current challenges in long-term durability validation of materials，reliability of intelligent monitoring systems and applicability of multi-scale models as well as special requirements of emerging application scenarios for Carbon Neutrality. This paper provides references for safe development of oil and gas and integrity management of subsurface storage and transportation facilities for energy transformation.