Device and method for slowly descending fish fries into pond in water body

The invention discloses a device and a method for slowly descending fries into a pond in a water body. The device for entering the pond comprises a fries input assembly and a pond entering assembly, the fry input assembly comprises a fry injection slide way, one end of the fry injection slide way is connected with an external fry bearing part, the other end of the fry injection slide way is located above the culture pond, the pond entering assembly comprises a fry lifting tank, the fry lifting tank is located below the fry injection slide way, and a release valve is arranged at the bottom of the fry lifting tank; a first fixed pulley is arranged at the top of the fry lifting tank, a second fixed pulley is arranged on one side of the first fixed pulley, a brake device is arranged on the first fixed pulley, a connecting pull rope is arranged on the first fixed pulley and the second fixed pulley, and the two ends of the connecting pull rope are connected with the fry lifting tank and the balance weight respectiv