The invention discloses a lint filtering device of a clothes dryer and an application method of the lint filtering device. The lint filtering device comprises an air duct, a lint filter and a smell containing unit. The air duct is formed in the clothes dryer, designed to be connected to a hot air unit of the clothes dryer and used for conveying hot air generated by the hot air unit; the lint filter is arranged at an air duct outlet, mainly composed of a frame with a supporting function and a filtering screen for filtering lint and provided with the smell containing unit; the smell containing unit can absorb and store a smell additive, and in the drying process, smell is exhausted along with the hot air; the smell containing unit is detachably arranged on the frame of the lint filter. The clothes dryer is arranged on the lint filtering device, has a function of filtering lint, can also add a corresponding smell for dried clothes and is simple in structure and convenient to install; in addition, the lint filtering device can be detached and replaced according to the demand, and the smell additive is easy to store and cannot be easily volatilized. According to the lint filtering device of the clothes dryer and the application method of the lint filtering device, the lint filtering device is more durable and effective during use.