The invention discloses a unit cell structure, an algorithm expression six-freedom-degree movement platform structure and a method of the algorithm. The method includes the following specific steps that firstly, the lengths of six rod pieces are known, and the value ranges of the six freedom degrees of upper platform poses are (x1-x2), (y1-y2), (z1-z2), (x'1-x'2), (y'1-y'2) and (z'1-z'2); secondly, the value ranges of the six freedom degrees are equally divided into n parts, and the poses on the upper platform have n6 conditions; thirdly, an inverse solution solving calculation method is used for solving the theoretical rod lengths corresponding to the n6 poses; and fourthly, the fact that the absolute values of the differences of the criterion-theoretical rod lengths and the practical rod lengths are smaller than or equal to epsilon is utilized, the theoretical rod lengths are compared with the practical rod lengths till a set of theoretical rod lengths meeting the criterion are obtained, and the upper platform poses corresponding to the theoretical rod lengths are the upper platform poses needing to be solved. The algorithm in the material crystallography is used for the six-freedom-degree platform kinematics, and the progress of the key technology of robotics and even intelligent manufacturing is facilitated.