On the basis of the accuracy evaluation's demand of single impulse radar and other ground measure equipment, model of the inherent accuracy of ballistic camera as Evaluation's comparison criterion on fairway of a Rocket-Flight are worked out. Three respects analysis follows:1) Will the criterion be able to be used? 2) In case of two laser ballistic camera having effective data ,where does the one ballistic camera be as criterion? Where does the two ballistic camera be as criterion? 3) How can the speed be evaluated? The formula ,calculation method's simplification as well as the curve figure of the error transfer of the criterion are given and analysed. The model have been successfully used in single impulse radar's accuracy evaluation. It is a typical case of the accuracy analysis.