The invention discloses a start control method for a working condition excitation system of a static frequency converter of a pumped-storage aggregate set. The start control method comprises the steps of: carrying out a 0-20mA simulation current signal sent by the static frequency converter to be used as a preset value, comparing the preset value with a rotor current feedback value, then sending to a start stage PID (Proportion Integration Differentiation) controller, outputting Uf through operation of the PID controller and then controlling a pulse trigger angle through anticosine calculation so as to control the conduction time of a thyristor to ensure that the voltage of a machine end stably raises. An excitation regulator is provided with a PID control model of working condition starting of the static frequency converter, and PID parameters of the PID control module only control the starting of the static frequency converter without controlling the regulation rule of the normal operation of the pumped-storage aggregate set, therefore, the reliability of the starting of the pumped-storage aggregate set is ensured while the stability of operation of the pumped-storage aggregate set is not influenced, the position of a motor rotor is favorably detected by the static frequency converter, the starting success rate of a motor is increased, and the safe and stable operation of the power supply is facilitated.