Abstract: With the increasing development of industrial production, the demand for gas sensors is growing. Given that triethylamine is easily harmful to the human body, it is important to develop a gas sensor that can effectively detect triethylamine. Considering the shortcomings of common gas sensors with high working temperature and high energy consumption, a gas sensing material that can quickly detect triethylamine at room temperature was proposed in this paper. Through the combination of electrospinning, heat treatment and in-situ chemical oxidation polymerization, the inorganic-organic composite, WO₃@polyaniline (PANI) nanofibers, was successfully synthesized with controllable component content. Scanning electron microscopy, X-ray diffraction, energy dispersive X-ray spectrometer and Fourier transform infrared spectroscopy were used to characterize the morphology, element content and functional groups of the as-prepared samples. The composite demonstrates fibrous morphology with PANI uniformly distributed on the surface of WO₃ nanofibers, forming WO₃@PANI core-shell structure. The WO₃@PANI composite nanofibers show good sensing performance to triethylamine at room temperature. In addition, excellent sensing properties are also achieved, such as excellent triethylamine selectivity, stable response under high humidity condition, wide concentration detection range (50-5000 μg/g triethylamine) and good response-recovery characteristics. Compared with sensing performance of pristine PANI and WO₃ nanofibers, the enhanced sensing response of WO₃@PANI composite nanofibers is mainly attributed to the p-n heterojunction formed between WO₃ and PANI.