In order to solve the problem of losing solution,a lot of multiplications of inverse matrices and a lot of solutions in the solution process of inverse kinematics of robot,a new inferential method for inverse kinematics of MOTOMAN manipulators is presented.The dual variable tangent function is used to avoid losing solutions in the process of deduction.The method avoids a lot of multiplications of inverse matrices,simplifies the solving process and reduces the computations.Additionally,the shortest distance rule is presented to choose a solution closest to the current manipulator for a number of inverse kinematics solutions.The research resuts have been applied successfully in a 6-DOF robot,which proves that the presented method is correct.