The invention discloses a simulation arrangement method of heaters in an electrical function box, relates to the technical field of electrical control, and aims to solve the problem that the reliability of running of equipment in the electrical function box is low due to the condensation phenomenon in the electrical function box. The simulation arrangement method of the heaters in the electrical function box comprises steps as follows: establishing geometric models of the electrical function box, heaters and ventilation windows; setting environment parameters and heater parameters; calculating and acquiring a relative humidity value corresponding to each area in the electrical function box according to the environment parameters and the heater parameters; judging whether the relative humidity value corresponding to each area in the electrical function box is smaller than 100%, and when the relative humidity value corresponding to at least one area in the electrical function box reaches 100%, optimizing the heater parameters until the relative humidity value corresponding to each area in the electrical function box is smaller than 100%. The provided simulation arrangement method of the heaters in the electrical function box is used for optimizing the heater parameters.