As the core of the informal system and its "local knowledge" characteristics, ideology has a great impact on the implementation of precision poverty alleviation and the performance achieved.Whether ideology is intrinsically consistent with the current formal system has a positive or negative influence of social and economic activities.Based on the perspective of transaction costs, it analyzes that how ideology affects precision poverty alleviation and further reveals that the mechanism of ideology which has negative effects in precision poverty alleviation in Liang Shan Yi Region. It’s believed that strengthening the development of education, improving people's cognitive ability and cultivating correct values,choosing the local elements with the concept of inclusive development and forming an atmosphere of sharing the beliefs,are the best ways to reduce the frictions between ideology and poverty alleviation policy.