In order to improve the functional properties of chickpea protein isolate (CPI), CPI was treated with high intensity ultrasound (HIU) under 450 W for different time(5, 10, 20 min). The emulsifying property of protein was improved obviously by ultrasonic treatment, the solubility of CPI was significantly increased from 7.5 mg/mL to 9.2 mg/mL, and the foaming capacity of CPI was increased to a maximum value of 163.33%. Moreover, the water holding capacity and breaking force of the heat induced CPI gel significantly increased from 58.40% to 75.75%, and 75.7 g to 254.3 g. HIU increased the α-helix content and decreased the β-sheet content of CPI. Moreover, HIU decreased the endogenous fluorescence intensity of the protein and the emission wavelength was red shifted by 5 nm, suggesting that HIU changed the secondary and tertiary structure of CPI. In addition, after ultrasonic treatment, the free sulfhydryl content, surface hydrophobicity and surface potential of CPI were increased. The particle size of CPI gradually decreased with extension of ultrasonic time. These results demonstrate the relationship between the structure and functional properties of CPI.