Automation in cooperative editing is of use for it relieves human work. Access control in cooperative editing with workflow (CEWW) is important but hard to achieve. A novel access control model, Activity based Cooperative Editing Access Control (ACEAC), is set up for CEWW, which is a dynamic, active, adaptive and context sensitive model. A fine-grained and content oriented abstract object, section, on which cooperative editing and control are based, is introduced. Six key components that represent essential information and mechanism for control are also put forward to manage participants, control resources, distribute permissions, assign roles and maintain access control list. The model fulfills activity execution control, avoids and coordinates collision in cooperative editing, ensures data concurrency and consistency, and also provides interfaces for workflow engine, cooperation server and version control server. A temporal CEWW system that takes the model as access control deals with automation work in cooperative editing well.