[Aim]  To investigate the structure and properties of cocoon silk fibers from Habrobracon hebetor, and investigate their potential as a silk resource. [Methods]  Multiple characterization techniques were used to analyze their morphology, secondary structure, silk protein composition, moisture absorption properties, and thermal properties, of H. hebetor silk. Scanning electron microscopy, combined with energy-dispersive spectroscopy, were used to observe the surface morphology and elemental composition of the silk. Fourier transform infrared spectroscopy and X-ray diffraction were employed to analyze the secondary structure of its proteins and its amino acid composition was determined to reveal characteristic features of its proteins. The capacity of the silk to regain moisture was measured to evaluate its hygroscopic properties. In addition, thermogravimetric analysis was used to assess its thermal decomposition behavior and thermal stability. [Results]  Scanning electron microscopy revealed that H. hebetor silk fibers are slender and uniform monofilaments with an average diameter of (1.39 ± 0.22) μm. Energy-dispersive spectroscopy analysis indicates that its main elements are carbon (66.95%), nitrogen (18.44%) and oxygen (12.59%), which is typical of a protein. Amino acid analysis showed that the silk protein is mainly composed of serine (33.3%), glycine (24.2%), and aspartic acid/asparagine (16.7%). The capacity of H. hebetor silk to regain moisture was 10.45% ± 0.26%, which is significantly higher than that of Bombyx mori silk (P＜0.01). Fourier transform infrared spectroscopy and X-ray diffraction results demonstrated that the secondary protein structures are predominantly β-sheets and β-turns. Thermogravimetric analysis indicates that H. hebetor silk has a thermal decomposition temperature of (317.13 ± 1.29) ℃, which is slightly lower than that of B. mori silk. [Conclusion]  The cocoon silk of exhibits a fine and uniform microstructure, a secondary structure rich in β-sheets and β-turns, excellent hygroscopic properties and favorable thermal stability. These findings suggest that it has the potential to be used in multifunctional natural silk-based materials. These findings provide theoretical support for the investigation and utilization of the silk produced by parasitoid wasps.