VDI2614/2634 is a kind of commonly method of precision evaluation for 3D optical measuring system .The national standard named measurement specification of optical 3D geometry for forgings & stampings and its dies is being formulated. A new method of evaluation for optical measuring system imposed on forgings/stamping has been proposed

the testing project has been drafted

then each group is considered as a single subsystem

that the minmax-difference， mean difference and mean square value of each group have been calculated. The system-relatively error of subsystem is defined because that mean difference is divided by measurement mean value

the accidence-relatively error of the subsystem is defined because that minmax difference is divided by measurement mean value. Relatively error and weight are considered completely

that the system error and accident error of the measurement system may be calculated. For the reunification of evaluation standard

the concept and calculation method which comprised of standardized system precision

standard accidental precision and standardized precision are put forward. The XJTUOM optical measuring system developed by ourselves has been evaluated by means of this approach

then the conclusion that the standard precision 0.89 is reached out. Formulating reference of national standard is provided with this approach.