The structure,the accident cause modules and the logical relationship between them are sorted out by reviewing and analyzing the relevant literature for the better popularizing and applying of 24Model. The research shows that,24Model has already passed four versions,such as 2005,2013,2015 and 2016. The 2005 version has not yet fully formed with unknown meanings and unreasonable logical relationship of modules. The 2013 version has built the basic framework,in which the logical relationship of the internal f...