The invention discloses a riveting machine automatic rivet feeding mechanism. The riveting machine automatic rivet feeding mechanism comprises a vibration feeder, an ejection rod mechanism, a conveying hose, a grating sensor and a riveting machine. The vibration feeder is located on the riveting machine. A material port of the vibration feeder extends to the material inlet side of the riveting machine. An L-shaped trough plate is connected to the front end of the material port. The grating sensor is mounted on the L-shaped trough plate. A rivet groove is formed in the L-shaped trough plate and is located in an ejection rod guiding path. The conveying hose is mounted on the riveting machine and is kept being vertical. A funnel is mounted at the top of the conveying hose. The funnel and the rivet groove are arranged oppositely. The situation that rivets are not blown in place due to too low air supply pressure is avoided; and meanwhile, the vibration feeder does not need an extra rivet blowing air supply and relative pneumatic elements, the structure of riveting process equipment is simplified, and the cost of the riveting process equipment is reduced.