The mechanism of cell action potential was explained by using the principle of potassium channel "origami windmill" model. It is inferred that ion channels should include at least two categories: One kind of channel is "special ion channel", its structure is like an origami windmill model. All cations passing through this channel rotate into the interior from one-way, only in and no out. Compared with K+, they have two states of "open" and "closed", When they are "open", their aperture is not less than K+ diameter. When "closed", their aperture is smaller than K+ diameter, but not smaller than Na+ diameter. The other channel is the "universal ion channel". All Ions passing through this channel unidirectional flow too, only out and no in. Compared with K+, they have two states of "open" and "closed", When they are "open", their aperture is not less than K+ diameter. When "closed", their aperture is smaller than K+ diameter, but not smaller than Na+ diameter. This model reasonably explains the whole process of action potential occurrence, and supports Hodgkin, Huxley 's experimental the results of action potential. This model does not support their explanation of the mechanism of action potential generation in cells and the core ideas of "membrane theory" and "ion theory". It negates the selective filter atomic model and the propeller model established by MacKinnon et al. It is tiped that the main role of "sodium-potassium pump" or "ATPase" is not responsible for the transport of Na+ and K+ from the inside and outside of the cell and maintaining cell membrane potential. The channels through which ions enter and escape cells are independent. This suggests that most channels may be sharing in the same direction by other inorganic ions and organic molecules.