AbstractTrustworthy software is delivered by enacting trustworthy software processes. The purpose of this paper is to propose an approach to modeling trustworthiness requirement‐oriented software processes. First, based on the aspect‐oriented modeling techniques, separation of concerns is used to separate the crosscutting activities and the core activities according to the different trustworthiness requirements and functional requirements. A goal‐oriented modeling and reasoning method for trustworthiness requirements to find the crosscutting activities that satisfy multiple trustworthiness requirements is presented. Then, base processes are modeled for functional requirements. The crosscutting activities for trustworthiness requirements are decomposed into processes or tasks and encapsulated in aspects that are woven into the base processes. In the weaving procedure, correct weaving methods between multiple aspects and between aspects and base processes are designed. Errors or mistakes of aspect‐oriented process modeling are prevented. Finally, trustworthy third‐party certification authority software is studied systematically in a case study, and performance evaluations are conducted to show the cost and effect of the approach.