The invention provides a method for identifying a signal machine in a railway drawing. The method comprises the following steps of: preparing a mold; acquiring reference primitive information and determining a comparison reference quantity; determining an RN in the reference primitive, AN and BN are used as comparison reference quantities; reading railway drawing information, identifying each annunciator primitive in the railway drawing; reading a correlation comparison reference quantity of each annunciator primitive; and then comparing according to the following steps: reading the referenceprimitive information, determining the numerical value of N in the reference primitive, establishing a forward rectangular coordinate system in the railway drawing, and carrying out forward directionand direction search to determine the number, position and direction information of signal machine primitives in the railway drawing. According to the signal machine identification method in the railway drawing, signal machine primitives are inquired and recorded based on the coordinate information of the railway drawing, the identification error rate is reduced through the coordinate identification mode, and meanwhile the identification efficiency is greatly improved.