Plant maintenance is a critical role in the success of manufacturing enterprises. As a new equipment maintenance mode, e-maintenance is treated as one of the most promising equipment maintenance mode for enterprises. Knowledge is structured experience and information, whose core value is to derive the better maintenance decision. To achieve secure knowledge sharing in e-maintenance, a Business-Process-Context-Based Knowledge Access Control (BPCBKAC) model was proposed. The model used \"Business process context\" as the intermediary of authorization to realize flexible and business-oriented knowledge access control.