The invention discloses an underwater propeller fault degree identification method based on time domain energy and time domain entropy of fusion signals. Two pieces of fault information on single aspects of underwater robot speed signal fault information and propeller control signal fault information are organically fused, then more comprehensive fusion fault information is obtained, multi-domainfault characteristics such as the time domain energy and the time domain entropy in the fusion fault information are extracted and used for establishing fault samples, finally, the fault samples are classified based on a support vector domain description algorithm, and the underwater propeller fault degree is obtained. The mapping relation between the extracted fault characteristics and the extracted fault degrees is unique, the propeller fault degrees can be classified, and the classification precision reaches 95% or above.