In this invention project, we used the brand new wireless network, combined with sensor to detect the remain amount of Intravenous-drip, and then combined the patient??s information, bed number, room number in the ward, finally combined with the QR code scanned through the Intravenous-drip bottle, then sent to the servo computer to compare with the information installed in the data base to prevent nursing staff form wrong injection, and can automatically to inform nursing staff to change the Intravenous-drip