The invention provides a printed circuit board. The printed circuit board comprises an input and output interface, a communication device and a power module. Adjacent signals in the input and output interface are isolated through a ground network of a first preset separation distance. A ground network of a second preset separation distance is adopted in isolation of the communication device. The power module comprises at least one power part, and copper is laid on multiple layers below the power part. According to the printed circuit board, ground network shielding protection is carried out on sensitive signals on the circuit board, the anti-jamming capability of the signals is improved, radiated interference on external devices is reduced, enough heat dissipation space, namely, a heat dissipation channel is provided for a heating element, and therefore a thermosensitive component is well protected, and the service life of the component is prolonged. The invention further provides an electric car.