The invention provides a drop sensor, which is mainly used for patients to hang drops. A detector is installed on the sub drop bottle, and the detector is electrically connected with an audible device. When the drop in the sub drop bottle is about to be used up, the detector detects the lower liquid level in the sub drop bottle, and immediately informs the buzzer on the audible device to send out a warning sound, so as to inform the medical staff to be more timely. Change the bottle.本創作係提供一種點滴感測器，主要係於病患吊點滴時之用，於副點滴瓶上安裝一偵測器，該偵測器電性連接一發聲裝置；當副點滴瓶內的點滴即將用罄時，偵測器偵測到副點滴瓶內較低的液位，即刻通知發聲裝置上之蜂鳴器發出警示聲響，以告知醫護人員及時更換點滴瓶者。
