A mouthpiece and an atomizing device including the mouthpiece are provided, the mouthpiece includes an upper cover body, a sensor assembly and a base, where both the upper cover body and the base are hollow structures which open at both ends; the upper cover body is sleeved on one end of the base; an inner surface of the upper cover body and an inner surface of the base jointly define an inner cavity of the mouthpiece; the sensor assembly is fixed in the inner cavity of the mouthpiece; an air passage gap is formed in the inner cavity of the mouthpiece; and the sensor assembly includes at least one sensor that functions to detect the temperature or humidity or both of the smoke. The mouthpiece can detect the temperature and/or humidity of the smoke in real time.