Taking three translational asymmetric (3-2SPS) parallel machine tool as the research object,the influence of the redundant linear sliding and redundant circular sliding on working space of machine tool was studied. A coordinate system of machine tool was established,the coordinates of redundancy slider of the two sliding modes were determined.In the same system, two different redundant sliding mode position inverse solution models of parallel machine tool were established.The inverse solution kinematic equation was obtained.Setting constraints to machine tool motion, MATLAB software was used to simulate the working space of the parallel machine tool by two redundant sliding modes.The influence of the two kinds of redundancy sliding mode on working space of machine tool was analyzed comparatively.