The invention discloses a non-linear windage yaw reliability calculation method based on a Monte Carlo insulator string. The method comprises the steps that a transmission line research object is set,and a rigid straight bar method is adopted to calculate a windage yaw angle value of the insulator string; a connection structure of a tower and the insulator string is established according to overhead transmission line norms, random variables involved in the connection structure are selected, and a distribution function corresponding to the random variables is determined according to the randomvariables; a geometric relation corresponding to the connection structure is established; an insulator string windage yaw failure function with the random variables is established; and a Monte Carlomethod is used to calculate the windage yaw reliability of the insulator string. The method has the advantages that reliability is good, the calculation process is simple, and the requirements of existing technologies can be met.