The selection of insulation materials in wire harness manufacturing directly affects product safety and service life. Firstly, the usage environment should be considered, such as high temperature, low temperature, humidity, or chemical corrosion scenarios. Corresponding materials with high temperature resistance (such as 150 or above), moisture resistance, or corrosion resistance should be selected, such as cross-linked polyethylene (XLPE) or polytetrafluoroethylene (PTFE). Secondly, the mechanical properties of the material are crucial, and it is necessary to evaluate its tensile resistance, wear resistance, and flexibility to ensure that the wiring harness is not easily damaged during installation or vibration. In terms of electrical performance, attention should be paid to dielectric strength and volume resistivity to avoid the risk of leakage. In addition, the environmental friendliness of materials is becoming increasingly important, and priority should be given to selecting halogen-free flame retardant materials that comply with RoHS or REACH standards. Cost and processability also need to be balanced, for example, PVC has low cost but poor temperature resistance, while silicone rubber is soft but expensive. Ultimately, it is necessary to comprehensively consider application scenarios, performance requirements, and cost budgets, and verify the compatibility between materials and wire harness structures through experiments to ensure long-term reliability.