In order to improve the effect of urban and rural regional spatial planning and resource allocation, we need to focus on the factor of urban and rural population flow. Therefore, this paper evaluates the effect of urban and rural population mobility and spatial planning under the background of big data. Based on the evaluation of the effect of urban-rural population migration, according to the evaluation principle of the effect of urban-rural population migration after the reform and opening up, the evaluation index system is constructed, the dimensionless processing of the evaluation index system is carried out, the evaluation index weight is calculated, and the evaluation index is quantified, so as to complete the effect evaluation of spatial planning. Finally, taking Tianjin as an example, the application effect of this design method is verified.