The invention discloses a platform door linkage device and method based on distance measurement. The linkage device comprises a train door detection module and a central controller; the train door detection module is arranged at the end, close to a train door, of a platform door and comprises at least two distance measuring sensors, and an array formed by the distance measuring sensors is not shorter than the train door; the distance measuring sensors are used for measuring the distance between the platform door and the side wall of a train in a preset detection cycle, and the side wall of thetrain coincides with the train door after the train door is opened; the central controller is used for separately comparing distance information acquired by each distance measuring sensor in the contiguous detection cycles, and the platform door is controlled to be opened when the distance measured by any one distance measuring sensor becomes smaller. According to the device and the method, whether or not the train door is opened or closed is judged according to the distance change between the platform door and the side wall of the train, correspondingly the platform door is intelligently controlled to be opened or closed without dependence on the linkage control over the train door, and the platform door linkage device and method are suitable for rail transit safety protection without information interaction between intelligent rails and other systems.