The author establishes a risk evaluation index system of technology innovation according to the character of technology innovation . In this index system, technology risk, the capability of coporate risk, market risk are taken into consideration as well as the situition of the interior and the exterior of coporate besides the difficulty of the technology. The index-weighted is calculated with AHP and the whole process of fuzzy comprehensive evaluation is developed , which gives the accurate evaluation for the echnology innovation risk and can be guided by an enterprise for control the risk. At last, an example is given.