The invention discloses a method for the performance evaluation and the residual life prediction of a rotating system of an automobile crane. The method disclosed by the invention is characterized in that under the condition of constant-speed rotation of the rotating system of the automobile crane, vibration signals of a hydraulic pump and a rotary speed reducer of the rotating system of the automobile crane are synchronously acquired; the power transmission time delay is obtained based on related analysis; the greater the time delay is, the worse the performance of the rotary system is. The method for the residual life prediction of the rotating system of the automobile crane is subjected to Gaussian regression modeling based on a dynamic transmission time delay value of the rotating system of the automobile crane of different service durations, a performance decay regression model of the rotating system of the automobile crane is obtained, and the residual life of the rotating system of the automobile crane is obtained through setting a time delay threshold value. The method disclosed by the invention has the benefits that the performance evaluation on the rotating system is performed from the perspective of overall operation efficiency of rotating operation of the automobile crane; the test method is simple, evaluation parameters are direct and effective, and the requirements for performance of instruments and equipment are not high.