直線導軌又稱線軌、滑軌、線性導軌、線性滑軌，用于直線往復運動場合，且可以承擔一定的扭矩，可在高負載的情況下實現高精度的直線運動。在大陸稱直線導軌，臺灣一般稱線性導軌，線性滑軌。主要用在自動化機械上比較多,像德國進口的機床,紙碗機,激光焊接機、機床的刀架，拖板等等,當然直線導軌和直線軸是配套用的。

        Linear rail, also known as line rail, slide rail, linear guide rail, linear slide rail, is used in linear reciprocating motion, and can bear certain torque, and can achieve high precision straight line motion in high load condition. In the mainland, it is called linear guide rail. Taiwan is generally called linear guide rail and linear slide rail. It is mainly used in automatic machinery, such as German imported machine tool, paper bowl machine, laser welding machine, tool holder of machine tool, trailing board and so on. Of course, the linear and linear axes are used.