Abstract: A thermal spraying apparatus includes a hollow pipe, an extrusion die, a piston, a helical pipe, a fluid supplying device, and a heater. The hollow pipe defines an accommodating space for accommodating a raw material. The extrusion die is connected with the hollow pipe. The extrusion die has a nozzle. The nozzle is in spatial communication with the accommodating space. The piston is movably accommodated in the accommodating space to push the raw material to pass through the nozzle. The hollow pipe is surrounded by the helical pipe. An end of the helical pipe is connected to the nozzle. The fluid supplying device is connected to another end of the helical pipe. The heater encloses the helical pipe and the hollow pipe for heating the helical pipe and the accommodating space.