It is proposed a method of cameras group calibration with pairwise bundle adjustment using one dimensional wand. The one dimensional wand is one of the simplest calibration tools with two distinguishing markers the distance between which is known. The wand with the markers moves unconstrained in the field of cameras group, acquiring the coordinates of the projections of the corresponding marker in each camera. Every two cameras are formed as a couple, which fundamental matrix, focal lengths, rotation matrix, translation matrix and scale factor can be estimated under a few of certain assumptions. Optimal solutions are obtained through the pairwise bundle adjustment. The group calibration result is demonstrated as a sort sequence of all of the couple calibration results in ascending order according to reconstruction errors. The couple as top ranked as possible will be used to reconstruct the object in application procedures. Experimental results show that the dual couple method has much more accuracy and maintain the same feasibility comparing with the other one dimensional object calibration methods.