Rail joint refers to the use and working performance of the joint connection is divided into the following types: ordinary joint, the most basic one, by two fixed length rail with cleats and other parts connected into a continuous track, between the two rail ends set 8 to 10mm rail seam, for rail thermal expansion and contraction. Due to the existence of rail joints, periodic impacts occur when the vehicle passes, resulting in the damage of the rail and track bed in the joint area, such as rail end collapse, peeling, saddle-shaped wear, track bed sinking, collapse and hardening. For this purpose, welded joints have been replaced on busy trunk lines. Profiled joints for connecting two rails with different cross-sectional heights. Power transmission connectors, used for automatic blocking and electrification of lots, power supply flow circuits. Insulated joints, used to automatically block the rail joints at both ends of the partition to block the current and prevent leakage. Freeze joints to prevent rail expansion. Glue joint, with high-strength adhesive, coated on the rail end and the contact surface between the splint and the rail, the rail and the splint glue are combined into a whole, and can play an insulating role. (7) Expansion joint, also known as temperature regulator, is used for track with large expansion at the end of the rail, track on the bridge with a span greater than 100m and seamless line expansion area on the bridge.