In order to ensure the safety and no leakage of the high-level radioactive solid waste such as hulls and end-pieces during the transfer and storage process, they need to be formed into compacts through processes such as sub-packaging, drying, and Ultra-pressing, and then placed into waste containers. After being filled, the containers are covered with inner and outer lids and sealed through welding to ensure the sealed storage of high-level radioactive waste and a certain degree of drop strength after welding. Therefore, a TIG welding machine was designed that can realize the automatic welding function of butt welds in a high-radiation environment. This machine utilizes two welding methods: self-melting back-up welding and wire-filling welding, to achieve the sealing of high-level radioactive solid waste container body, inner lid, and outer lid. The automatic welding machine consists of a suspended welding head, a hoisting device, a container placement platform, an automatic tungsten electrode replacement device, and a welding power supply. It has the functions of automatic positioning, weld seam confirmation and real-time tracking, automatic tungsten electrodes replacement, and automatic alarm. It also has a certain degree of tolerance for gaps between the container body, inner lid, and outer lid. The consumable parts of the automatic welding machine (such as tungsten electrode clamps, wire reels, etc.) can be quickly replaced using a glove box. Through the experiments of the automatic welding equipment, the functionality, the welding processes and parameters have been verified, providing technical support for the treatment and storage of high-level radioactive solid waste.