The present invention discloses an indoor semantic map updating method and system based on semantic information extraction. The method includes: issuing a crowdsourcing task to all mobile terminals; waiting for any mobile terminal to execute the crowdsourcing task, and receiving a task result thereof; preprocessing the task result to obtain a common key frame sequence; extracting an accurate text sequence from the common key frame sequence; and updating an indoor semantic map according to the common key frame sequence and the accurate text sequence. The present invention can encourage the mobile terminal to execute the crowdsourcing task, and update the indoor semantic map and the text semantic information at a lower cost.
