Research conclusions: (1) This track - laying machine unit integrates the long - rail track laying and the tie arranging， and is mainly composed of the long rail tractor，the host and auxiliary machines，tie carrying car， rail /tie transportation train， power system， hydraulic system， electric control system and brake system. (2) The operation mode of the host machine is designed as the " arranging the tie in cluster and laying the track in step" by using the innovative mechanism of the laying the tie evenly and sleeper arranging machine， and by using this method， the problems of high failure rate and the tie damage caused by the impact can be solved and the costs of the machine manufacture， operation and maintenance can be much cut. (3) The modularization design and manufacture are adopted to this machine unit，resulting in convenient and flexible assembly， disassembly and transferring to other site. (4) This machine machine is made in Chins with adopting the existing mature technology for long rail track laying， computer control technology and the mechatronics technology， so that the convenient use and maintenance can be achieved. (5) This research results is available for laying the ballast and ballastless tracks with the 500 m long rail or below.