Abstract: TIG welding has many advantages such as stable welding process, good weld quality, no spatter and suitable for all-position welding, but it also has disadvantages such as small welding penetration, slow welding speed and low cladding rate. In order to overcome the shortcomings of small TIG welding penetration, a variety of new deep penetration TIG welding methods were proposed to increase the welding penetration. The latest research progress of active TIG welding, K-TIG welding, DP-TIG welding and magnetic controlled deep penetration TIG welding were summarized, the existing problems of deep penetration TIG welding were summarized, and the future research directions of deep penetration TIG welding were prospected.