The invention discloses an adaptive cooling device for manufacturing a fiber loose tube at a high speed, the adaptive cooling device comprises a water tank, a water volume control unit, a position adjusting unit and a controller; the water tank is used for cooling and shaping the fiber loose tube, and the internal cooling water in the water tank in real time immerses the fiber loose tube; the water volume control unit is used to control the water volume of the water tank to in real time ensure that the cooling water in the water tank can immerse the fiber loose tube; the position adjusting unit is used to adjust the distance between the water tank and an extruder head, thereby adjusting the water inlet surface of a stretching zone to precisely control the cooling and shaping size of the fiber loose tube; the controller is used to control the water volume control unit and the position adjusting unit to work. The present invention also provides an adaptive cooling method for manufacturing the fiber loose tube at the high speed. The adaptive cooling device can precisely control the cooling and shaping size of the fiber loose tube and ensures the dimensional stability of the fiber loose tube in the speed increasing stage.