The invention discloses an airflow crushing unit. The airflow crushing unit is characterized in that the airflow crushing unit comprises a feeding mechanism, a crushing mechanism, a screening mechanism, a collecting mechanism and an auxiliary mechanism; the feeding mechanism comprises a feeding hopper and a screw feeder, a lower end discharge outlet of the feeding hopper is connected with a feed inlet of the screw feeder, and the screw feeder is horizontally arranged; a feeding transition bin is arranged between the feeding mechanism and the crushing mechanism, and the feeding transition bin is vertically arranged and comprises a first feed inlet and a first discharge outlet; the first feed inlet and the first discharge outlet are each provided with a first pneumatic butterfly valve, and a discharge outlet of the screw feeder is connected with the first feed inlet of the feeding transition bin. According to the airflow crushing unit, liquid nitrogen is used for directly cooling materials; therefore, the materials to be processed become brittle, elasticity is reduced, the brittle point is reached, and an ultrafine powder product is obtained.