Educational land plays an important role in the increasing urban density growth and urban boundary expansion of Chinese cities. However, determining the size of campus construction land is still a pure political behavior, and the lack of quantitative research regarding the sustainability of campus expansion leads to unpredictable inadequacy or massive waste. In addition, suitability of campus land scale is closely related to the comfort of outdoor space, especially in cold regions. Based on particle swarm optimization, this paper tries to find a relatively accurate basis for the sustainable development of campus construction in extremely cold regions, in order to provide recommendations for current construction activities in colleges and universities, and enhance the comfort of campus external space. More importantly, the research can provide accurate prediction of the overcrowding degree in campus for decision makers in campus construction, so that they can formulate the policy correctly and timely, such as when the expansion of campus construction land is needed, the proper students number of the existing campus land scale, and the proper size of the campus.