By means of the technology of inside-beam powder feeding, the formation technology of double-inclined-walled parts (DIWPs) with small gapsis is investigated. By using the methods of sequentially independent accumulation path, normal layering, and non-dislocation accumulation, the DIWPs are formed. The experimental results indicate that the technology proposed can increase the forming efficiency of DIWP, save metal powder, and ensure the thickness uniformity of thin-walled parts and the gap stability of the double inclined walls. The formed parts have smooth surfaces, uniform morphology, no cracks, no holes and no other defects, and uniform microhardness distributions.