Vehicle-mounted PTC water heater

The invention relates to the technical field of vehicle-mounted heaters, and particularly provides a vehicle-mounted PTC water heater. The vehicle-mounted PTC water heater comprises a water channel assembly and a control assembly, the water channel assembly comprises a lower bottom shell, a fixed aluminum shell and a plurality of heating modules, and the control assembly comprises an adapter plate, a control panel, a high-voltage connector, a low-voltage connector and an upper cover. The aluminum oxide ceramic shells are used as direct separation of the heating units and the liquid medium, the insulation problem is avoided, the thermal resistance is reduced, the size and weight are reduced, meanwhile, the heating power can be greatly increased, meanwhile, the multiple staggered aluminum oxide ceramic shells are matched with the guide rib grooves to form the effect of a water baffle, and the heating efficiency is improved. Therefore, the liquid medium entering the heating installation groove is guided and drai