The invention relates to a firefighter breathing sound monitoring earphone and provides a firefighter body state evaluation method. The firefighter breathing sound monitoring earphone includes a soundcollection module, a bone conduction sound playback module, a memory module, a button module, a narrowband Internet of Things module, an STM32 processor module, a power management module and a lithium battery module. When in the fire rescue scene, a firefighter wears the breathing sound monitoring earphone, the breathing sound of the firefighter in the fire rescue scene can be collected by the breathing sound monitoring earphone for the first time, and the physical state of the firefighter is analyzed and identified to evaluate whether the firefighter is in danger. The firefighter breathing sound monitoring earphone is advantaged in that a physical state evaluation problem of the firefighter in the fire rescue scene is effectively solved, characteristics of flexible expansion, convenientcarrying, wireless interconnection and low cost are realized, the accurate identification rate of the physical state of different firefighters is improved, the false acceptance rate of firefighters' physical state identification is reduced, and the casualty rate of the firefighters is reduced.