Abstract: On the basis of summarizing the existing control techniques of switching converter, the control techniques are classified into four basic-type controls, i.e. voltage-, current-, charge-, and flux-mode control, and combination-type control, according to the four fundamental physical quantities existed in the circuit. In accordance with the implementation of duty ratio, there are two basic modulations which are pulse width modulation（PWM） and pulse frequency modulation（PFM）. It is proposed that control techniques of switching converters are composed of combining "control" and "modulation". Operation principles, intrinsic characteristics, inherent relations, advantages and disadvantages of basic-type control and combination-type control are systematically investigated by the concept of combining modulation and control. They can provide the application reference for the modulation and control techniques of switching converters. According to duality principle, a series control techniques for constant output current which are analyzed in brief are derived from the existing control techniques.