Object-oriented��method is more and more widely used in the system design. The requirement and characteristics of the monitoring and processing system of a coaxal pilotless helicopter are analyzed .The system is an important component part in pilotless helicopter. In the course of executing task, the director can control the pilotless helicopter depending on the parameter of flying and equipment . Based on object oriented analyses, object oriented design and object oriented programming a detailed design scheme of the monitoring and processing system is discussed. With its high performance in reusability, improvability, testability, portability, maintainability, expandability, it has been tested to be able to meet the demands of flight.