The invention discloses a method for building a rotary motor model of a two-level voltage source converter. The method comprises the following steps of establishing an expression of a sine reference wave; establishing an expression of a triangular carrier wave according to a frequency ratio N of the carrier wave; calculating a quantity and types of commutator segments in the rotary motor model of the two-level voltage source converter according to the frequency ratio N of the carrier wave; by a natural sampling method, calculating moments t1, t2, ..., t2N corresponding to natural intersection points of the triangular carrier wave and the sine reference wave; and calculating the sizes of the commutator segments and a spacing between the adjacent commutator segments, and finishing the building of the rotary motor model of the two-level voltage source converter in combination with quantities of windings and electric brushes, and electric angle relationships of the windings and the electric brushes. The method is used for definitely representing a working principle and a physical concept of the two-level voltage source converter, and deepening intuitive understanding of engineering technicians to running control characteristics of the two-level voltage source converter.