A dust-proof structure of a cone crusher below a cone core of the cone crusher includes primarily a dust ring which is suspended under the cone core, allowing the dust ring to operate concurrently with the cone core. Lubricant oil is provided between the dust ring and the cone core, enabling the dust ring to be tightly attached with a lip part of the cone core and operate successfully. The dust is prevented from entering into the cone crusher by ineffectiveness of a dust-proof function. Furthermore, a dust collar is attached under the dust ring, and an adjustment washer is provided between the dust collar and the cone core. When the dust ring is worn out, the adjustment washer is removed, and the dust ring is tightened again by screwing elements, thus preventing the dust from entering into the cone crusher due to the ineffectiveness of the dust-proof function.