In order to make the flexible production line quickly produce different products, shorten the measure time of different machines, and to explore the feasibility of the mechanism as a measuring mechanism in the working space, an industrial robot test platform with high precision, large measurement range and portability is proposed. A 3 SPR-6 SPS series-parallel mechanism with multiple degrees of freedom is proposed. The bottom layer of the mechanism is a 3SPR parallel mechanism and the upper part is a 6SPS parallel mechanism. The inverse kinematics analysis of the mechanism is carried out, and then the working space is solved by modeling and simulation with software. Nine inverse kinematics formulas of the mechanism are listed, and 18 limit positions and 30 boundaries of the workspace are obtained. The workspace of the mechanism described in this paper is large in volume, continuous without cavity, regular and symmetrical shape, and it is feasible to be used as a test platform.