PURPOSE: To provide the method which easily generates CRT picture data for railway signal device in a short period.

CONSTITUTION: This method is characterized by connecting a CRT display information recognition device 13 to a CAD system and generating CAD signal data where CRT display information of start and end points of each track circuit, the track division number, the character code of the track circuit name, character coordinates, the character string length, etc., with one track circuit as the unit in the case of relations to track circuits or CRT display information of the code name of a signal symbol, the type name, symbol arrangement coordinates, the signal name, name coordinates, etc., with one signal as the unit in the case of relations to signals is recognized by CAD data.