The invention discloses a dispensing method used for an injection powder bottle and a dispensing device. The dispensing method includes the steps of making preparations, inserting needles to the injection powder bottle and a transfusion bag respectively, sucking a part of liquid medicine in the transfusion bag into the injection powder bottle, pulling out the needles after sucking is finished, shaking the injection powder bottle to enable the liquid medicine and injection powder to be uniformly mixed and turning the injection needle bottle by 180 degrees, inserting the first syringe needle into the injection powder bottle upwards, injecting the liquid medicine in the injection powder bottle into the transfusion bag, pulling out the first syringe needle, and dispensing under the assistance of a first liquid level controller and a second liquid level controller. The dispensing device comprises a catheter, a first syringe needle and a second syringe needle, the first syringe needle comprises a transfusion needle hole and a ventilation needle hole, the ventilation needle hole communicates an air pipe with an air pump, the first syringe needle, the second syringe needle and the air pipe are provided with a first clamping head, a second clamping head and a third clamping head respectively and the first clamping head, the second clamping head and the third clamping head are convenient to clamp. According to the dispensing method, needle insertion is easy to carry out, operations are convenient to carry out, the first syringe needle and the second syringe needle of the dispensing device are simple in structure and low in cost, liquid medicine can be automatically dispensed when the first syringe needle and the second syringe needle are matched with a mechanical automatic control device, and dispensing efficiency is improved.