The invention discloses a method for preventing power frequency magnetic field startup of PCBs (Printed Circuit Boards) of an electricity meter. The method comprises the following steps: providing N PCBs; arranging the N PCBs in parallel in the electricity meter; arranging an electrical assembly on each PCB to form X closed loops; calculating the areas Sx of the X closed loops; overlapping the X areas Sx to obtain a minimum Sn. The PCBs can resist 0.5mT interference of power frequency magnetic fields in any direction, a production process is easy, and batch production can be realized easily.