<p>This paper reviews the most efficient and direct solution to existing assembly techniques in three-dimensional (3D) printing and classifies them into macroscopic, microscopic, and mesoscopic categories. This paper discusses the challenges and possible methods for simultaneously achieving multi-material, multi-precision, and large-volume products. 3D printing with high-speed production and cost-effectiveness offers new manufacturing possibilities. Printing materials with different properties can be used to produce a variety of products with reduced weight and improved performance; however, 3D printing faces limitations in simultaneously creating multi-material parts, printing components with varying precision, and accommodating diverse product sizes. Strategies have been developed to overcome the limitations of 3D printing, focusing on hardware improvements and the exploration of 4D printing. However, its widespread implementation awaits ongoing experimentation and investment. This review illustrates how assembly involves precise part connections for robust structures in various manufacturing processes to satisfy specific application requirements. Traditional assembly is characterized by low technical requirements and minimal specialized tools or staff. Considering 3D printing characteristics and application size distribution, this study discusses three assembly methods: macro-assembled, micro-assembled, and meso-assembled structures. Secondary light curing enables modular manufacturing for large-scale and microfluidic systems, and step-by-step printing involves multiple stages to improve the surface activity and adsorption of stable chemical bonds between different materials. Over the past several decades, 3D printing has made significant advancements and found applications in various fields, including construction, machinery, and medical treatment. This paper illustrates assembly technologies that can satisfy these multi-material, multi-precision requirements.</p>