Abstract: To construct a set of effective evaluation index system and evaluation method of rural public security risk, which is the basic work of promoting rural public security construction scientifically. The paper considers the rural environment influence factors on the bearing capacity of rural public safety around 4 dimensions of bearing capacity of rural ecological, infrastructure, social and population, and puts forward the evaluation indexes and the projection pursuit (PP) risk assessment model of the rural public safety risk. The paper uses the accelerated genetic algorithm (AGA) to improve the standard projection pursuit method to achieve rapid optimization of projection index function, on this basis, the paper also uses the regression analysis method to fit between time series and one-dimensional projection value to get the prediction curve of one-dimensional projection value, and then the projection values carried by the theory of information diffusion to spread into the 4 risk levels. This paper uses the method of risk entropy to calculate the development trend of rural environmental carrying capacity for evaluating the risk size of rural public security. The verification results show that the improved PP evaluation model can expose the structural characteristics of multidimensional index to the maximum extent. The author fits between one-dimensional projection value and time series, and find the fitting precision reaching 0.0271, and therefore, high fitting precision can ensure the rural environmental bearing capacity risk entropy credibility, so that also ensures the assessment result of the rural public safety risk assessment reliably in a certain extent. The conclusion is:that the rural public security risk assessment can reflect the actual situation and development trend of rural public safety risk around the perspective of rural environmental carrying capacity. The assessment model is a simple and effective method with high precision, stable effect and consistent with reality, so it can provide decision basis and method reference for the department of public security management.