Abstract: Positive temperature coefficient (PTC) thermal ceramics are a kind of key electronic functional ceramics, which are widely used in heating elements, sensors, circuit protectors, temperature controllers, and electrical demagnetization, because of the excellent characteristics. The positive temperature coefficient thermistor (PTCR) prepared by using BaTiO₃ as the host materials is a type of PTC elements with a large amount at present, showing the important research significance. The classification and advantages-disadvantages of the PTC heat-sensitive materials were elaborated in the article, the PTC effect, heat-sensitive mechanism, and semiconductivity principle of the BaTiO₃-based PTC materials were introduced, and the research status of the BaTiO₃-based PTC heat-sensitive ceramics was summarized at home and abroad. The effects of peak shifting agent, donor doping, acceptor doping, and sintering process on the BaTiO₃-based PTC thermal ceramics were analyzed. The application principle and application of the PTC thermal components were summarized in the related fields, and the lead-free PTC thermal ceramics were looked forward.