The invention provides a PTC heater. The PTC heater comprises a shell, a liquid inlet and a liquid outlet are formed on the shell; a cooling liquid channel is formed in the shell, a first flow stopping component and a second flow stopping component are arranged in the cooling liquid channel; the first low stopping component and the second flow stopping component are orderly arranged at intervals along a water flow direction; the first flow stopping component extends to a second inner wall from a first inner wall of the channel, and a gap is formed between the first flow stopping component andthe second inner wall; the second flow stopping component extends to the first inner wall from the second inner wall of the channel, and the gap is formed between the second flow stopping component and the first inner wall; and the first inner wall and the second inner wall are opposite to each other; a PTC heating element is arranged in each of the first flow stopping component and the second flow stopping component, and an electric connecting end of each PTC heating component extends to the outside of the corresponding flow stopping component. The new energy vehicle heater based on the PTC heating resistor has the advantages of being high in heating efficiency, large in power and high in security.