In order to research the influencing factors of falling accidents during building construction, and analyze the social network relationship between the factors and the con struction subjects, 207 investigation reports of falling accidents from 2013 to 2019 were se- lected to extract relevant data, the control structure of the systems-theoretic accident model and processes (STAMP) was combined with the framework of the event analysis of systemic teamwork(EAST), and the social network,task network,information network,control network and composite network model of the falling accident system were constructed. Through social network related indicators, the key nodes of each network and the combined nodes that are most likely to cause falling accidents were found.There search results show that the nodes among network shave strong connections,construction unit,construction personnel,insufficient education and training,and not wearing safety items are at the core of the network, the combination of the construction unit and insufficiente ducation and training are the most typical combination of falling accidents.