The non-agricultural transition of rural migrant workers constitutes the main source of China's economic growth in recent 30 years.Under the confining conditions of the existing systems and knowledge,the rural migrant workers adopt the form of group migration. Based on the consanguinity,region and professional organization,the rural migrant workers go along with each other in groups,saving the information cost of transition as well as the risk share,while increasing the probability of knowledge spillover.Th...