Up to now, there are different views on the length of F201 left lateral strike-slip fault in South of Zhongwei, Ningxia province. Through comparison study on the rapture belt of M7 1/2 South of Zhongwei earthquake in 1709 from eight aspects in this paper,it is ditermined that the length of F201 is at least as same as the rapture length of the South of Zhongwei earthquake in 1709. The earthquake rapture starts from East to Yingpanshui as west end and extends eastward to Shuangjingzi, then expands to nearby Shijuangou at east to Liugangjing, the overall east-west length of the rapture is 110 km. The rapture is composed of five secondary shear faults, Xiaohongshan-- Gushanzi, Xiliangtou-- Yaoxianzigou, Kulongshan-- Jiangou, West to Qingtuoai-- East to Sikouzigou and Shanyangchang--East to Liugangjing.