In order to investigate the surface powder adhesion process of 316L stainless steel by laser direct metal deposition, the type of powder adhesion was analyzed by high-speed camera. The influence of powder feeding rate, gas flow rate and linear energy density on powder adhesion in single-channel multilayer deposition was studied quantitatively by single factor test method. The results show that, adhesion powder mainly includes two types: molten solution escaping from molten pool and unmelted powder adhesion. With the increase of powder feeding rate and the decrease of powder feeding gas flow rate, the adhesion degree of powder on the side surface of thin-walled parts increases. However, the degree of powder adhesion is insensitive to the change of laser linear energy density. With laser power of 700W, scanning speed of 700mm/min, powder feeding rate of 13.54g/min, powder feeding gas flow rate of 14L/min and defocusing rate of +22mm, powder adhesion on the surface of thin-walled parts by laser direct metal deposition is less. The results can be used as an important basis for improving the surface quality of 316L stainless steel products.