In order to realize the standardization and informationization of safety evaluation, the software system of construction risk evaluation is developed based on the gray Euclid relation theory model and C/S system structure. Six modules, that are system login module, risk data management module, risk assessment module, evaluation results query module, and system management module are designed and the software is applied to construction site. It is shown that the software system of construction risk assessment based on grey Euclid relation grade can effectively improve the safety evaluation efficiency of construction site, thus the means of construction safety management is greatly improved.