Traditional animal husbandry is struggling to meet the surge in global protein demand. To promote the highvalue application of novel protein resources, the functional properties of five insect proteins were determined, and their structural characteristics were investigated using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), amino acid composition analysis, Fourier-transform infrared (FT-IR) spectroscopy, and scanning electron microscopy (SEM). Results indicated that among the five samples, Acheta domesticus (house cricket) possessed the highest protein content at 67.84%. Locusta migratoria manilensis (Oriental migratory locust) and A. domesticus proteins exhibited high water-holding capacity (WHC) and oil-holding capacity (OHC). Cryptotympana atrata (black cicada) nymph protein showed the highest foaming capacity and foam stability, A. domesticus protein exhibited the highest emulsifying capacity, and L. migratoria manilensis and Tenebrio molitor (mealworm) proteins achieved the highest emulsion stabilities. SDS-PAGE analysis revealed that L. migratoria manilensis and A. domesticus proteins had relatively high molecular weights (55~130 kDa), whereas C. atrata nymph protein had a lower molecular weight (10~25 kDa); moreover, the molecular weight was positively correlated with WHC and OHC. C. atrata nymph protein possessed the highest total amino acid content and a relatively high ratio of hydrophobic to hydrophilic amino acids, contributing to their excellent foaming capacities and foam stabilities. FT-IR spectroscopy showed the presence of strong absorption peaks for T. molitor protein and Bombyx mori (domestic silk moth) chrysalis protein at 2925 cm-1 and 1654 cm-1, respectively. These peaks corresponded to the -CH2- asymmetric stretching vibration and the amide I band, respectively, influencing their functional properties. SEM revealed differences in micro-morphology across the five samples. Particle size was smallest in L. migratoria manilensis protein, increasing the tendency to form network structures and thereby enhancing its WHC. In conclusion, the structural characteristics of insect proteins are closely related to their functional properties, with A. domesticus and C. atrata nymph proteins demonstrating the most favorable performance.