The technology of degreasing and removing miscellaneous protein in chicken feet by ultrasonic extraction was studied using degreasing rate, collagen loss and effect of removing miscellaneous protein as evaluation index. The hydroxyproline, proline and glycine of chicken feet after and before treatment were determined by HPLC. The effects of V(petroleum ether)∶V(ethanol)=1∶1/NaCl solution method, alkaline lipase solution method and NaOH solution method on the degreasing rate were investigated. Furthermore, the solid-liquid ratio and ultrasonic time/times were optimized. It was found that V(petroleum ether)∶V(ethanol)=1∶1/NaCl solution method showed the highest degreasing rate, followed by alkaline lipase solution method, while NaOH solution method showed the highest collagen loss. Then, a two-step treatment method of V(petroleum ether)∶V(ethanol)=1∶1/ alkaline lipase solution was designed and the optimized process was as follows: in the first step, V(petroleum ether)∶V(ethanol)=1∶1, solid-liquid ratio 1∶4 (g/mL), ultrasonic extraction for 3 times, each time using the new solvent ultrasonic 10 min; in the second step, 0.05 mol/L NaOH solution with mass fraction of 2.5% lipase (pH=8), solid-liquid ratio 1∶2 (g/mL), consecutive ultrasonic time 40 min. Under these optimum conditions, the degreasing rate was 96.48%, and the collagen loss was 9.31%. Besides, the proportions of hydroxyproline, proline and glycine in chicken feet by the two-step treatment method were similar to those in the gelatine extracted by hot water from the chicken feet after degreasing.