The invention discloses a power device and a drug adding device. The power device is used for acting on a drug adding tank, the drug adding tank is provided with a trigger rod and a first binder and comprises a force applying rod, a second binder and a drive mechanism. The drive mechanism is configured to enable the force applying rod to push and abut against the trigger rod of the drug adding tank or be separated from the trigger rod and used for enabling the second binder to be bound with the first binder of the drug adding tank and driving the first binder to rotate or enabling the second binder to be separated from the first binder.