The error analysis of blade surface is very important during the process of turbine blade manufacture. Firstly, key technologies of surface inspection were studied, and the crucial parameters automation extraction algorithm for blade section from measured data was proposed. Next, the registration method between measured data and computer aided design (CAD) model was given. Meanwhile, several indexes of evaluation for blade were put forward, such as profile error, angularity error, camber error and twist error. Finally, the error analysis system of turbine blade was developed based on UG. Successful experimental results show that this system can improve the efficiency and quality of blade surface inspection.