The invention relates to a train security monitoring system and a train security monitoring method, which belong to the field of train security monitoring. The train security monitoring system particularly comprises a cabin monitoring center, a station monitoring center and a plurality of onboard cameras, wherein the cabin monitoring center includes a storage unit, a processor unit, a communication unit, and a video structured processor unit. Through comparison between the structured data of passenger face information obtained by the processing with the pre-stored passenger information, whether a passenger in the video data has a behavior of illegally riding the ticket is thus determined, and real-time, reliable and efficient passenger check-in and ticket checking work is realized.