The relevant issues of e-commerce precision poverty alleviation have drawn wide attentions from government, social public and academic community. This paper starts with concept and system of e-commerce precision poverty alleviation, then analyzes the operation mechanism of the system through development of the operation mechanism and surveys of the situations in Liangshan Prefecture of Sichuan Province, and then explore the factors affecting the operations of various subsystems. It is concluded that the e-commerce precision poverty alleviation system can help transform and upgrade local industries, help develop local rural industries, help boost rural e-commerce development, and help poverty-stricken regions shake off poverty and become prosperous.