An integral medicine compounding mechanism and a medicine compounding method for an injection powder bottle. The medicine compounding mechanism comprises an infusion bag needle (3) and an injection powder bottle needle (4). The infusion bag needle (3) is a dual-hole needle comprising a first through hole (31) and a second through hole (32). The first through hole (31) and the second through hole (32) are respectively connected to a first catheter (9) and a second catheter (10). The injection powder bottle needle (4) is a dual-hole needle comprising a third through hole (41) and a fourth through hole (42). The third through hole (41) and the fourth through hole (42) are respectively connected to a third catheter (7) and a fourth catheter (8). A first check valve (11) for allowing liquid to flow from the first catheter (9) to the third catheter (7) is disposed between the first catheter (9) and the third catheter (7). A second check valve (12) for allowing liquid to flow from the fourth catheter (8) to the second catheter (10) is disposed between the second catheter (10) and the fourth catheter (8). The medicine compounding mechanism has a simple structure, is convenient to connect and has a high medicine compounding efficiency because the medicine compounding structures are connected as a whole, the medicine compounding mechanism can be integrally replaced at a time after medicine compounding is completed, and replacement time is saved the medicine compounding procedure is also simplified, an infusion bag (1) and an injection powder bottle (2) can be connected at a time, operations are easy, the medicine compounding efficiency is greatly improved, and liquid medicine is prevented from being splashed in the medicine compounding process.La présente invention concerne un mécanisme de composition de médicament intégré et un procédé de composition de médicament pour un flacon de poudre pour injection. Le mécanisme de composition de médicament comprend une aiguille de poch
