A Buck-boost converter presents rich nonlinear behaviors when some parameters are changed,which will seriously affect the stability of the system and degrade the power quality of the system output. In this paper, according to the load characteristics of actual converters, the nonlinear behavior of buck-boost converter with an inductive load is deeply studied, and an analysis and optimization control method of nonlinear behaviors of a buck-boost system with an inductive load is proposed. Firstly, the discrete iteration model of the system is established and its Jacobian matrix is obtained. Then, the possibility and type of nonlinear behavior of the system are determined according to the amplitude and distribution of eigenvalues of the matrix. Then, the feedback signal is formed by the difference between the output delay value of the system and its own value, and the signal is made to pass through the proportional link, summation link and logarithmic link so as to form an optimal control signal, and is applied to the system in the form of negative feedback. Finally, the optimal control parameters are determined based on the stability criterion and the system is controlled. In order to verify the effectiveness of the proposed method, a large number of simulation experiments are carried out. The results show that by the proposed method can be well suppressed the nonlinear behavior of the system, extended the stability boundary of the system, and improved the power quality output by the system.