Abstract: The provided is a self-adaptive tensioning wearable monitoring device for poultry and livestock, where a flexible loop band is threaded through a self-adaptive tensioning module and a monitoring module, and is connected end-to-end inside the self-adaptive tensioning module; a surface of the monitoring module is provided with a wireless sensing module; the monitoring module is slidably connected to the flexible loop band; the self-adaptive tensioning module includes one end fixedly connected to a fixed end of the flexible loop band and the other end telescopically connected to a movable end of the flexible loop band; the self-adaptive tensioning module is disposed at a poultry/livestock back; and when the flexible loop band is tightened, the wireless sensing module at the surface of the monitoring module is in close contact with a skin in a poultry/livestock body temperature measurement area.