Quantifying survivability for network system helps to give more accurate evaluation and compare different system or monitor the change of system survivability. This paper puts forward a new method that combines uncertain AHP with fuzzy comprehensive assessment technology to build an assessment model for network survivability. Using uncertain AHP acquire the weight value of each factor, and then the comment scores are fuzzed through membership function of fuzzy theory and construct fuzzy matrix, finally we will obtain the quantities evaluating result by adopting fuzzy comprehensive assessment technology. An instance is given to prove the validity and feasibility of using the method for network survivability assessment.