Research conclusions：Through the simulation calculation, the highest train speed of the No.3 rapid rail line is 79 km/h and the biggest braking distance is 657 m. However, considering the necessary safe distance, the maximum blocking section length will be 700m that can satisfy the requirement of train operation, and considering the requirements of the train returning and the train speed, the minimum blocking section length around the kaifaqu Station will be 200m that can satisfy the requirement. With fixed automatic block, the speed grade of signal equipment should be consistent with the train speed without limitation of the normal train operation for increasing the train speed.