The invention discloses a traffic monitoring video storing method in an HDFS based on event intensity. The traffic monitoring video storing method is characterized by comprising the following steps that an intelligent camera obtains traffic monitoring data, detects traffic events and sends traffic video streaming data and event type description information included in the data to a video server; the video server encodes and segments the video data after receiving the video streaming data sent by the camera, a video file is generated, and the file is marked with the event type according to the event description information of the video data; the video data are uploaded to the HDFS; after receiving a data storage request, a Name Node in the HDFS calls a data placement strategy based on the event intensity to select a target data node for the data file to be stored; the file is stored in the target data node selected in the third step. The problem of node load unbalance caused when the HDFS stores mass traffic monitoring videos can be solved, and accordingly, the traffic monitoring data can be efficiently stored.