The invention discloses a planet shaft intelligent identification flexible assembling system and an operation method thereof. The system comprises a charging station, a C1 planet shaft press-fitting station, a C3 planet shaft press-fitting station and a riveting pressing station; and the charging station, the C1 planet shaft press-fitting station, the C3 planet shaft press-fitting station and theriveting pressing station are connected with a control system through data lines correspondingly. A plurality of feeding robots are adopted for cooperation and connected into a whole system in seriesthrough a transfer robot, thus, multiple actions are conducted simultaneously, and the high machine tool takt is achieved. An air cylinder displacement device is adopted, and the system is compatiblewith many models through one set of equipment. Due to the fact that the system adopts a camera photographing detection technology, the feature points of the end faces of planet shafts are identified,and multi-visual error prevention and angular correction of the press-fitted end faces are achieved. The transfer robot adopts the design of double clamp heads, thus, the clamp heads can conduct the charging and discharging actions at one time, the high flexibility of the whole system is achieved, and full-automatic planetary gear train press-fitting and riveting pressing are completed.