The invention discloses an ore crushing device with a dust falling mechanism. The ore crushing device comprises a crushing cylinder and a
grinding roller; the crushing cylinder is a conical
hollow cylinder with a wide upper part and a narrow lower part; a discharging
pipe is embedded in the central axis of the crushing cylinder; the upper part of the crushing cylinder is communicated with a
blastpipe; and the blast
pipe is tangentially communicated with the crushing cylinder. Through the arrangement of the crushing cylinder which is wide in upper part and narrow in lower part and is in a conical cylinder shape, a central
pipe extending into the crushing cylinder, the blast pipe and a blast cylinder linked with a rotating shaft, the
rotational flow is formed in the crushing cylinder for
cyclone sedimentation and collection of dust, so the random floating of the dust is avoided, and a good dust falling effect is achieved; through the arrangement of an eccentric
extrusion disc, an impactplate and a guide cover, the ore crushing speed and effect are guaranteed; through the arrangement of a discharging box, a columnar cavity and an
impeller roller, while quantitative discharging is conducted, the crushing effect is guaranteed, and the dust is prevented from overflowing from the feeding hopper, thereby further improving the dust falling effect.