The invention discloses a fire therapy device for hair and an application method of the device. The device comprises a shell, a sliding shell, handles, connection rods, push plates, push rods, a firesprayer and an igniter. The interior of the shell is divided into a storage cavity, a first containing cavity and a second containing cavity, openings are formed in the upper and lower ends of the shell respectively, and the storage cavity is communicated with the first containing cavity through a first air hole; the first containing cavity is communicated with the second containing cavity througha gap, the sliding shell is arranged in the first containing cavity, and the upper segments of the two handles are crosswise hinged to the opening of the lower end of the shell; the bottoms of the two connection rods are hinged to the tops of the two handles respectively, the tops of the two connection rods are hinged to the bottom of the sliding shell, and the bottoms of the two push plates arefixedly arranged on the inner bottom wall of the sliding shell; the tops of the two push plates penetrate through the sliding shell and extend out of the shell, clamping plates are arranged on the twopush plates respectively, and one end of each push rod is hinged to the outer side wall of the corresponding push plate; the other end of each push rod is hinged to the inner side wall of the first containing cavity, the fire sprayer is arranged at the opening of the upper end of the shell, the air inlet end of an air channel is communicated with a second air hole through a hose, and the igniteris arranged on the inner bottom wall of the sliding shell.