The invention provides a ready-to-use device for an acid fracturing fluid. The ready-to-use device for the acid fracturing fluid comprises a mixing tank, wherein the inlet end of the mixing tank is in parallel connection with an additive unit, a thickening agent unit and an acid fluid unit, and the outlet end of the mixing tank is in series connection with a first centrifugal pump, a first buffer tank, a second centrifugal pump, a third pneumatic gate valve, a second buffer tank, a fifth pneumatic gate valve and a discharge pump. A first pneumatic gate valve is connected between the outlet end of the acid fluid unit and the inlet end of the mixing tank in series. A second pneumatic gate valve is connected between the outlet end of the acid fluid unit and the inlet end of the discharge pump in parallel. A fourth pneumatic gate valve is connected between the outlet end of the first buffer tank and the inlet end of the discharge pump. Four functional areas are respectively arranged in the two buffer tanks, and first stirrers and snakelike blocking plates are arranged in the functional areas. The device achieves the ready-to-use demand of the acid fluid, the prepared acid fluid is free of layering and agglomeration, and the quality of the prepared acid fluid is improved. In addition, by means of the device, acid unloading and fluid preparation links in the acidization process can be omitted, the acidization transformation effect and operation efficiency can be improved, and the production cost can be reduced.