The method provides a method and a system for determining load of upper hanging points on a downlead in a substation. The method comprises the steps of: respectively measuring load reverse force values of an upper hanging point and a lower hanging point on the downlead with scales when the upper and lower hanging points are in different horizontal spaces; obtaining payoff ratio of the downlead by calculating according to the measured load reverse force values of the upper and lower hanging points on the downlead and the payoff length of the downlead; paying off according to the payoff ratio of the downlead, and determining the reverse value of the downlead support; and calculating the reverse value of the downlead support, thereby obtaining the load values of the upper hanging points of the downlead. The method and system for determining load of upper hanging points on downlead in substation solves the technical problem that the size of the upper hanging points of the downlead cannot be accurately obtained in the prior art, and provides convenience for researching V-shaped insulator chains and designing grading rings.