The invention relates to a full-automatic relay piece press-assembling machine. The full-automatic relay piece press-assembling machine comprises a machine frame. A power distribution control cabinet is arranged at the bottom of the machine frame. A conveying device is arranged above the power distribution control cabinet. A product guide rail is matched with the left side of the conveying device. A discharging groove is matched with the right side of the conveying device and connected with a discharging conveying motor. The product guide rail is in fit connection with a product vibration discharging plate. Three elastic piece guide rails are arranged on the front side of the conveying device. The elastic piece guide rails are connected with elastic piece vibration discharging plates, and picking and placing devices matched with elastic pieces is arranged at the tail ends of the elastic piece guide rails. The picking and placing devices are further matched with the left portion of the conveying device. A press assembling device matched with products is arranged on the upper portion of the right portion of the conveying device. Automatic discharging of the elastic pieces is achieved through the elastic piece vibration discharging plates and the elastic piece guide rails, the elastic pieces are grabbed through the picking and placing devices and accurately jointed with products on the product conveying guide rail, and then the products and the elastic pieces are conveyed into a machining device, so that manpower is greatly saved, and meanwhile, the situation of neglected assembling is avoided.