3D printing has many advantages. Its biggest feature is that it can produce complex structural parts with extraordinary ideas. It can greatly reduce the application of materials and reduce the weight of parts on the premise of ensuring their strength. The structural design of the parts plays an important role in giving full play to the advantages of 3D printing. Structural design requires us to break the traditional design concept, give full play to imagination and creativity. Based on the existing data reports and the experience of some engineers in the industry, this paper recommends several structural design concepts of 3D printing parts for you. Modular structure is made up of some unit structure connected by some nodes. It can not only save materials and realize printing requirements, but also meet the requirements of physical strength, mechanical stability and selfbalance. Its advantage is that it can be mass-produced and made of recyclable materials, which not only protects the natural environment, but also can be effectively used in daily life.