Abstract: A micro-cavity liquid-phase shearing device for preparing quasi-two-dimensional materials includes a movable plate system, a fixed plate system, a feed liquid external circulation system, a driven gear system and a charging barrel. The movable plate system includes a movable plate unit and a driving gear. The fixed plate system includes a fixed plate unit and a support. A tank of the movable plate unit has a primary shear cavity, an annular micro-gap between a movable plate of the movable plate unit and a fixed plate of the fixed plate unit is defined as a secondary shear micro-cavity. The feed liquid, which flows outside the feed pipe through the liquid discharge port thereof, is primarily sheared in the primary shear cavity by the movable plate system, and then is secondarily sheared in the secondary shear micro-cavity by the movable plate and the fixed plate, and then returns to the charging barrel.