A cyclone dust collecting device includes a dust collecting box and a separator. The dust collecting box includes a dust entrance and a cavity formed by extension in a first direction. The dust entrance communicates with a dust exhaust channel of a host machine. The separator includes a dust inlet and a cyclone tube. The dust inlet communicates with the dust entrance. The dust inlet is configured to guide the dust exhaust airflow into the cyclone tube. The cyclone tube extends in a second direction and is at least partially disposed in the dust collecting box. The cyclone tube includes a dust outlet and an air outlet. The dust outlet is located in the cavity and the air outlet communicates with an outside of the dust collecting box. The second direction obliquely intersects the first direction.