In this paper, the Potential Agriculture Production index is introduced to estimate the scale of population migration caused by climate change by analyzing the change of Potential Agriculture Production index.We found that, for the changes of Potential Agriculture Production caused by climate change, circum-Bohai-Sea region, mature industrialized region and the industrializing region as the main regions of emigrating population will face a severe labor shortage.In addition, this paper also constructs a multi-regional CGE model, and analyzes the impacts caused by the change of population distribution pattern on regional economy, regional gap and the residents' welfare.The results show that the economic growth rate of the population immigrating regions has been accelerated; correspondingly, the economic growth rate of the emigrating population region has been reduced, and the greater the population migration scale, the greater the impact on the economy; population migration expands the inner-regional gap, and narrows the inter-regional gap, however the overall regional gap is somewhat reduced.