With the rapid rise of mobile communication technology, rich communication services develop rapidly. The explosive growth of rich media data poses new challenges to the traditional centralized information transmission system. All kinds of users will have new demands for data processing tasks in RCS, and require the security and strong traceability of processing results. In view of the above problems, based on the reasonable needs of users in RCS scenarios, this paper proposes an optimization policy of RCS processing task offloading and resource allocation based on blockchain. Blockchain technology is used to realize certificate storage, and DRL method is used to jointly optimize system energy consumption and resource overhead. Through the system modeling and simulation verification, the feasibility of the scheme is finally proved.