The invention provides an automatic welding machine of an aluminum-nickel compound piece of a lithium ion battery cover plate, consisting of a feeding mechanism A, a feeding turnover mechanism B, a turnplate mechanism C, a detection mechanism D, a nickel piece feeding mechanism E, a spot-welding machine F, an ultrasonic welding mechanism G, a banking mechanism H and an automatic control mechanism, wherein the feeding mechanism A, the feeding turnover mechanism B, the turnplate mechanism C and the detection mechanism D are arranged on the tabletop of the automatic welding machine; the nickel piece feeding mechanism E, the spot-welding machine F, the ultesonic welding mechanism G and the banking mechanism H are arranged on the turnplate mechanism C; the aluminum-nickel compound piece is placed on the lithium ion battery cover plate through the feeding mechanism A, the feeding turnover mechanism B, the turnplate mechanism C, the detection mechanism D and the nickel piece feeding mechanism E; and the lithium ion battery cover plate is automatically welded with the aluminum-nickel compound piece through the spot-welding machine F, the ultrasonic welding mechanism G and the banking mechanism H. The invention ensures that the whole process flow realizes the automation, changes the traditional mode for manually finishing miscellaneous work, librates the large amount of labor force, greatly improves the work conditions, greatly increases the yield, greatly reduces the manufacturing cost and simultaneously and effectively ensures the quality of products.