Automatic welding device and method for diamond tool bit

The invention provides an automatic welding device and method for a diamond tool bit. The automatic welding device comprises a base, wherein a welding head is arranged above the base; the top of the welding head is connected with a first air cylinder used for achieving lifting; a feeding roller is further arranged above the base; the feeding roller is connected with a motor; an upper pressing roller is arranged above the feeding roller in a matched mode; a saw blade is arranged between the feeding roller and the upper pressing roller, and a plurality of tool grooves which are arranged at equalintervals are formed in one side of the saw blade in the length direction; a tool bit library is further arranged above the base, and the tool bit library comprises a plurality of tool bits; a secondair cylinder is arranged on one side of the tool bit library and is used for ejecting the tool bits in the tool bit library and feeding the tool bits into the tool grooves; a microswitch used for identifying the positions of