Abstract: With the development of vehicle to the intelligent and networked direction, vehicle Ethernet began to be applied. The operating characteristics, structural design and manufacturing process of the vehicle Ethernet cable were introduced. For the difficulty of longitudinal conversion loss(LCL) and longitudinal conversion transfer loss(LCTL) in this cable manufacturing, focusing on the above two indicators of conductor material, processing process, the selection of twist machine and other key elements were discussed, and based on the transmission performance measured data of cable that manufactured by us is better than requirements of standard.