The invention discloses a bike decorative lamp assembly. The bike decorative lamp assembly comprises a flame lamp and a wind driven generator connected to the tail of the flame lamp and used for supplying power to the flame lamp. The flame lamp comprises a shell in the shape of a circular pipe, a radial support which is integrally formed on the inner side of the middle of the shell, a reflecting cover arranged on the inner side of the front end of the shell, and a center LED installed at the inner bottom of the reflecting cover. A flow guiding ring is formed on the portion, located at the rear of the reflecting cover, of the inner wall of the shell. A gap larger than 5 mm is reserved between the periphery of the reflecting cover and the inner wall of the shell. The outer wall of the reflecting cover is an arc-shaped convex face used for guiding airflow. The front end of the reflecting cover is in the shape of a shrinking opening with the outer portion wider than the inner portion. An electric push rod used for controlling the interval between the reflecting cover and the flow guiding ring is connected between the center of the support and the rear end of the reflecting cover. A water storage tank is connected to the lower portion of the middle of the shell. The face, facing the interior of the shell, of the water storage tank is provided with a micro-hole ultrasonic atomizing piece. The bike decorative lamp assembly can achieve a vivid simulated jet flame effect.