Wearable device for detecting and warning wearer of target entity

The invention discloses a wearable device for detecting and warning a wearer of a target entity, and the device comprises a wearable carrier which is provided with an LED lamp, an alarm, a vibration motor, a controller, a battery pack, and three PIR sensors. The PIR sensors are used for detecting whether an object is triggered to enter the range of the sensor or not, setting a threshold value of triggering time and sending detected information to the controller; the controller is used for receiving information sent by all the PIR sensors, judging whether a target object is a human being or notafter receiving a signal of the object sensed by any PIR sensor, controlling the LED lamp, the alarm and/or the vibration motor to be turned on if the target object is the human being, and controlling the LED lamp, the alarm and/or the vibration motor to be turned off when the triggering time is less than a threshold value; if not, controlling the LED lamp, the alarm and/or the vibration motor tobe kept in an off state.