The invention discloses a butt welding method for workshop columns under the humid environment. The butt welding method is characterized by comprising the following technological steps of (1) construction preparation, wherein before welding, a welding area is cleaned, the cleaning range is the area 30 mm to 50 mm away from a welding line, a grinding wheel is adopted to carry out grinding to remove oxide scales, metallic luster is exposed out, and impurities such as water, rust and oil contamination affecting the welding quality are removed; (2) initial positioned welding, wherein before main welding, initial positioned welding is carried out, integral combined tack welding is carried out, and the positioned welding quality should be consistent with the quality of the main welding line; (3) technology and butt welding determining, wherein according to the butt welding technology of H-type steel workshop columns, butt welding is carried out on an upper column (3) and a lower column (4) along a butt welding line (5), and according to the butt welding sequence, flange plates (2) are firstly welded, and then a web (1) is welded. The butt welding method has the advantages that due to effective combination of the welding process and the welding method, the welding quality and the working efficiency are improved, quality defects are reduced, and one-time welding percent of pass is improved.