The assembly of the cutting machine is the last production process of the machine. The quality of the electromechanical product must ultimately be guaranteed by assembly. In order to ensure that the machine or instrument can be assembled smoothly and achieve the predetermined assembly accuracy and functional requirements, it can be realized from two aspects of design and assembly process. When designing the dimensional accuracy and geometric accuracy of mechanical components, the dimensional tolerances and geometric tolerances of the relevant components, that is, the assignment of assembly tolerances, should be determined economically and reasonably by comprehensive analysis and calculation. In the process of mechanical precision design, the assignment of assembly tolerances can be solved by using the principle of size lead and the corresponding analytical calculation method. In the assembly process, DJ uses advanced assembly processes or methods during the assembly process. To ensure assembly accuracy requirements.