Abstract: Based on the mechanism of acrobatic erecting poles, this paper makes use of phase plane method and human controlling experience, puts forward an obvious imitating-human intelligent control method used to control one stage inverted-pendulum which combines qualitative analysis and quantitative estimation, and then abstracts controlling rules of one stage inverted-pendulum. By introducing "equivalent cart" concept, the analytical method is readily extended from one stage inverted-pendulum control system to double-inverted pendulum system, triple-one and even more. The theoretical analysis is the same as the test result. So the qualitative method used to analyze inverted-pendulum based on phase plane is feasible.