In this study, with the development of new technology and new layout, relaxed static stability aircraft has been widely used. In this paper, the research history of relaxed statically stabilized aircraft is reviewed, the flight quality is calculated and analyzed, and its modal characteristics are different from those of naturally stabilized aircraft. Based on the evaluation of flight quality, this paper summarizes the basic principles and methods of flight quality evaluation, gives the differences and common points between the evaluation of aeroplane and the traditional aircraft, and puts forward the quality evaluation method based on the parameters of the pilot model. Taking the conventional layout aircraft as an example, the relaxation of static stability can be achieved by shifting the center of gravity backward, the quality evaluation based on the same task is carried out according to the two states, and the evaluation results based on the driver model are obtained. The results show that the parameters of the driver model identified after the relaxation of static stability are much larger than those of the natural stability aircraft, indicating that the driver’s evaluation is very low. At the same time, it is shown that the task-oriented pilot evaluation is an effective way to evaluate the relaxed statically stable aircraft.