Fish-farming escape prevention filtering device

The utility model discloses a fish-farming escape prevention filtering device which comprises a device body. The bottom of the device body is fixedly provided with three steel columns. The three steel columns are sleeved with prism-shaped escape prevention devices. The bottoms of the prism-shaped escape prevention devices are connected with a water inlet pipe and a water drain pipe. When the water drain pipe is turned off, the water inlet pipe is turned on, water is injected into prism-shaped frames and flows into a pool along tapered holes in steel plates, the number of the tapered holes is decided according to the displacement of single holes to make the total displacement be the same as the water inflow of the water inlet pipe, and fishes can be prevented from swimming reversely and escaping effectively due to the fact that the spatial tapered holes are formed, and the external hole diameter is small; in the same way, when the water inlet pipe is turned off, the water drain pipe is turned on, water flows to drain holes in the bottom through the tapered holes, and the filtering function can be achieved due to the fact that the outer ends of the tapered holes are small holes.