The invention discloses an automatic kitchen knife blank welding machine, and relates to the technical field of kitchen knife welding. The automatic kitchen knife blank welding machine comprises a main machine placing cabinet, a machine shell, an X-axis linear module, a Z-axis linear module, a Y-axis linear module, a mounting bracket and a switch, wherein a PLC control system and a welding main machine are arranged in the main machine placing cabinet; the machine shell is arranged on the main machine placing cabinet, and an opening is formed in one longitudinal side of the machine shell; the X-axis linear module is arranged on the main machine placing cabinet, is located in the machine shell, and penetrates through the opening along the longitudinal direction; and the Z-axis linear module is arranged at one transverse side of the X-axis linear module, located at one end, in the machine shell, of the X-axis linear module, and distributed in the vertical direction. During use, the welding efficiency is high, the welding quality is good, and the harm of welding radiation to the body of a welder is small.