The non synchronous swaying of compact overhead conductors is the direct cause of phase to phase wind deflection flashover accidents. However, compared to the research on wind deflection response of single-phase conductors and insulators, the theoretical study of non synchronous swaying of different phase conductors is still relatively lacking, and the essential mechanism is not yet clear. To explore the mechanism of asynchronous swaying of overhead conductors, a calculation model for wind deflection swaying of overhead conductors under strong wind conditions with lateral displacement excitation at the gear end was established. The nonlinear asymptotic solution of the steady-state response of the model was derived, and the mathematical relationship between gear end excitation and conductor response was intuitively demonstrated. The parametric response characteristics of asynchronous swaying of overhead conductors were analyzed, and the time history response curve and parametric response line graph of asynchronous swaying were drawn through engineering examples. Research has shown that lateral displacement excitation at the end of the gear can change the gravity parameters of the wind deflection motion of overhead conductors, which can lead to the occurrence of asynchronous swaying phenomena of different phase conductors. The dynamic response amplitude of overhead conductors is directly proportional to the amplitude of displacement excitation and horizontal tension at the end of the span, and inversely proportional to the span and unit mass of the conductor.