The invention discloses a lead structure of a manganese-copper shunt, a PCB, and a layout structure of the PCB. The first current sampling end and the second current sampling end of the manganese-copper shunt are located on the same side of the manganese-copper shunt. The second current sampling end is interfered with by an external alternating magnetic field. A first sampling signal line forms a circular line on the PCB arranged in parallel with the manganese-copper shunt and is connected with the AD sampling end of a chip with a second sample signal line in a parallel or twisted manner in order to introduce external alternating magnetic field interference into the first current sampling end such that the first current sampling end is subjected to external alternating magnetic field interference of the same magnitude as that of the external alternating magnetic field interference of the second current sampling end. By changing the layout way of the current sampling end of the manganese-copper shunt on the PCB, the interference of the alternating magnetic field on the second current sampling end is introduced into the first current sampling end so that the interference on the first and second current sampling ends are canceled out so that the sampling interference of the alternating magnetic field on the manganese-copper shunt is prevented.