Abstract: This paper introduces a kind of insert tube diameter is 5 mm industrial video endoscope,the design,the design process of lens of image sensor,lighting the way,bending mechanism,insert the tube and power and other technical parameters are discussed,and expounds the main design process,through the test,contrast,analysis,calculation and other means of reasonable technological parameters.Right,is obtained,through the “block” design concept,at the same time to meet the portability and function extension two requirements.