The Geometric algebra model R^* (3,0,1) combines the benefits of dual quaternions and conformal geometric algebra, i.e., dual quaternions can compute faster while comformal geometric algebra have same translation algorithm for points and planes as well as have algorithm to compute sign distance between points and planes. A new inverse kinematic of industrial robots algorithm is proposed based on R^* (3,0,1) model, i.e., the unique solution of inverse kinematic of industrial robots is determined by the sign distances between joints and three singular planes, and the sign distances can be computed by R^* (3,0,1) model. This new algorithm can find unique solution without comparing a preferred one which is widely applied in general inverse kinematic solution. This new algorithm has advantages, such as be able to compute the sign distance to the singular planes, simple, high speed to compute unique inverse kinematic solution, effectively when applied to practical robot motion control. This algorithm is numerical verified on PUMA 560.