Evaluation model and evaluation methodology of comprehensive index about water environmental safety are adopted to evaluate the water environmental safety situation in Kunming between 2001 and 2011. The evaluation results show that: from individual evaluation results, we could conclude that problems in ecological safety, water quality safety and water quantity safety begin to emerge in Kunming, from comprehensive evaluation, the comprehensive index of water environment safety in Kunming declines year by year, which indicate the water environmental safety situation in Kunming is not optimistic. How to solve water environmental problem becomes one of the important issues in sustainable development of Kunming.