The study of the action potential of cardiomyocytes is as important as the study of nerve fiber cells. The theoretical basis of the action potential of cardiomyocytes is the ionic theory formed by nerve fiber cells. Its core point of view: the decline phase of the action potential of cells is dominated by K+ outflow. Applying the principle of the K+ channel “origami windmill” model, the mechanism of action potential generation of nerve fiber cells has been reasonably explained, and a point contrary to the ion theory has been drawn: the phase of the action potential decline is dominated by K+ influx. Similarly, applying the principle of the K+ channel “origami windmill” model can also give a reasonable explanation for the mechanism of action potential generation of cardiomyocytes. The difference between cardiomyocyte action potential and nerve fiber cell: In addition to K+, Cl-, Na+, the process of generating cardiomyocyte action potential also involves the participation of Ca2+. Ca2+ inflow in the rising phase will shorten the depolarization time; Ca2+ inflow in the falling phase will prolong the repolarization time. K+, Ca2+ space substitution proportion: rotate into 2 K+, squeeze out 3 Ca2+, and 4 extra negative charges in the cell, the proportion is 2: 3: 4; Conversely, squeeze out 2 K+, rotate into 3 Ca2+, 4 extra positive charges the cells, the proportion is 3: 2: 4. Na+, Ca2+ space substitution proportion: rotate into 1 Na+, squeeze out 1 Ca2+, and 1 extra negative charges in the cell, the proportion is 1: 1:1; Conversely, rotate into 1 Ca2+, squeeze out 1 Na+, there is 1 more positive charge in the cell, and the proportion is 1: 1: 1. Application of “origami windmill” model principle, can reasonably explain the cardiomyocytes action potential generation mechanism, further proveding “origami windmill” the model theory, “the theory of dove-like particles”“the theory of braincell activation” of science.