Abstract: The platformdoor control system has been widely used in urban rail transit lines, but with the continuous improvement of urban rail transit automation operation level, the number of domestic fully automatic operation lines is gradually increasing, and the existing platform door control system has been difficult to meet the operation requirements of fully automatic operation mode. The platform door control system should not only implement the alignment and isolation from the train door, but also meet the relevant requirements of Safety Integrity Level(SIL) 2 in terms of reliability and safety. This paper designed intelligent platform door control system for fully automatic rail transit lines to realize the alignment and isolation between platform doors and train doors, and adopted the "two out of two" design framework to improve the reliability and safety of platform door control system, at the same time, supported the operation scenario of mixed running of various vehicles to meet the requirements of platform door control system for fully automatic rail transit lines.