Currently, the urgent task is developing the methods and tools for increasing Smart Parking software system security. The purpose of this study is conducting analysis of requirements for Smart Parking System software security in order to find the bottlenecks and parts of the software that are most vulnerable to external threats and develop the methods and tools for increasing their security. The paper proposes the method of increasing Smart Parking software system security based on integrating the middleware in Smart Parking System software architecture. The proposed method takes into account all the criteria for Smart Parking System software security, i.e. parameters of safe access to the database, client program security, server security and API security and provides a complex solution for increasing the safety of Smart Parking software system. The proposed method differs from the known ones in that it allows taking into account all the criteria for increasing the Smart Parking System software security in complex using security middleware.