Engineering projects often face risks from technology, economy, nature, social and other aspects. Risk factors are of interdependence and interaction, so they are very difficult to be quantified. The paper describes a risk evaluation method for engineering projects based on fuzzy set theory which uses respective fuzzy numbers to evaluate the factors. The primary weights of factors and evaluation of alternatives are determined by applying fuzzy numbers. The results are consistent with the results calculated by conventional risk evaluation method. The research demonstrates that the method is objective and accurate, and is of an application value in the risk evaluation for engineering projects.