Abstract: There are no unified assessment standards of progressive collapse due to the complex mechanism of progressive collapse both at home and abroad so far． The adaptability of the evaluation index of antiprogressive collapse capacity specified by Guidelines for Collapse Control Design of Steel Structures with High Ｒedundancy of Japan to the prefabricated steel frame structures with inclined support joints was verified by 3 examples of 4-span and 5-story prefabricated steel frame structures with inclined support joints． Based on the subject of a nine-story prefabricated steel frame structure with inclined support joints，corner column，short side middle column，long side middle column and inside middle column were removed with the alternative load path method，the performance evaluation of antiprogressive collapse was conducted with performance evaluation method raised above，the result showed that structures performance of resisting progressive collapse turned out to be able to meet the need，the structures antiprogressive collapse performance after removing corner column was much better than that of removing inner column． In addition，the safety margin of trussed beam was lower than that of the column．