Aiming at problem of hand-eye calibration of a freedom redundancy snake-like arm robot, a method that independent of serpentine arm’s motion parameters to calculate the hand-eye relationship between vision system and the end-flange was presented. With the assist of external binocular camera system, the hand-eye relationship was obtained by establishing closed-loop transformation of external camera, end-flange and visual navigation system. Firstly, 3D coordinates of marked points was calculted based on the principle of stereoscopic vision. Secondly, by using of quaternion method, the transformations between external camera system and end-flange, external camera system and visual navigating system were obtained. Finally, the hand-eye transformation was calculated by creating closed loop. Experimental results indicate that the jamming originated from poor motion control precision caused by freedom redundant of snake-like arm robot was avoided, and the calibration precision meet the designed requirements.