Abstract: This study was aimed to determine the optimal conditions of ultrasonic-assisted alkaline extraction of wheat germ protein and enzymatic hydrolysis of wheat germ protein, and analyze their structure and antioxidant activity. Defatted wheat germ was used as raw material, and ultrasonic-assisted alkaline extraction was applied to study the effects of ultrasonic temperature, time, and frequency on the extraction rate of wheat germ protein with the extraction rate of wheat germ protein as an indicator; the enzymatic process parameters of wheat germ protein were optimized by response surface methodology with the degree of hydrolysis as an indicator; and the potentials, structures, and antioxidant activities were determined in vitro. The optimized conditions of ultrasound-assisted alkaline extraction of wheat germ protein were as follows: ultrasonic temperature 40 ℃, time 20 min, frequency 40 kHz, and the extraction rate of wheat germ protein could reach 68.42%; The optimum technological conditions of wheat germ protein hydrolysis were as follows: enzymatic hydrolysis time 2 h, pH 8.4, temperature 51 ℃, enzyme addition 7 000 U/g, the degree of hydrolysis reached 41.73%. Zeta-potential analysis showed that the potentials before and after hydrolysis were both negative and the absolute value changed significantly. The structural analysis of UV and IR spectra revealed that the characteristic absorption peaks of wheat germ protein were red-shifted and the internal structure and hydrophobic region were changed after enzymatic hydrolysis. The IC₅₀ of the enzymatic hydrolysates of wheat germ protein for the scavenging ability of DPPH radicals, hydroxyl radicals and ABTS⁺ radicals were 0.0581 mg/mL, 0.108 5 mg/mL and 0.104 1 mg/mL, respectively, the reducing power for Fe³⁺ reached a maximum value of 0.69 at 0.16 mg/mL. The enzymatic hydrolysates of wheat germ protein showed certain antioxidant properties in vitro, which provided a basis for further exploitation of wheat germ resources.