In the process of civil aircraft development, the implementation of accessibility design requirements is not in place, which may lead to some aspects of aircraft design defects, and constantly exposed after being put into operation, affecting the maintenance economy. With the continuous development of virtual reality technology and artificial intelligence technology, using virtual maintenance technology, through the construction of realistic virtual environment to analyze the maintainability of virtual prototype, maintainability design evaluation can be carried out in the development stage. Based on virtual maintenance technology and from the perspective of civil aircraft accessibility design, a defect analysis method of accessibility design is established by comprehensively considering five aspects: accessibility of maintenance area, accessibility of maintenance personnel, accessibility of maintenance tools, accessibility of maintenance components and accessibility of component details; the criteria of accessibility analysis results were given; the accessibility design evaluation in the development process was realized; the design defects were found out and the design improvement was made in time to improve aircraft maintainability. Finally, taking a certain type of aircraft power supply equipment as the object, this method was used to carry out maintenance accessibility analysis, and an application example was given to verify the feasibility of this method.