The invention provides a method for calculating icing weights of transmission conductors. The method comprises the following steps of: S1, taking a cross section of a conductor as a research object, and dividing a boundary of the cross section of the conductor into n surface infinitesimals; S2, acquiring environmental icing parameter of the transmission conductor; and S3, calculating an icing weight mice (i) of the ith surface infinitesimal in a time step length according to the acquired icing environmental parameter, and calculating an icing weight M of the transmission conductor according tothe following formula (as shown in the specification), wherein L is a length of the conductor and T is a total icing time. Through above method, icing conditions of transmission conductors can be monitored in real time, and the icing weights, icing thicknesses and icing shapes can be correctly calculated, so that benefit is brought to adopt corresponding protection measures so as to ensure the stable operation of the whole power grid system and prevent the production and life loss caused to the society by icing, and the whole calculation process has the characteristics of being high in efficiency and high in precision.