A space fixed point rotational freedom degree analyzing mechanism comprises a ball body, a slide block, movable slide channels, sliders, an X-shaft, a Y-shaft, a Z-shaft, an X-shaft plate, a Y-shaft plate, a Z-shaft plate, indicators, a pin and nuts. The ball body is provided with a Z-shaft slide groove, an X-shaft slide groove and a Y-shaft slide groove, the Z-shaft slide groove is vertical to the X-shaft slide groove and the Y-shaft slide groove, and the ball body and the Z-shaft can relatively rotate around the pin. The Z-shaft, the X-shaft and the Y-shaft are mutually vertical and connected to the X-shaft plate, the Y-shaft plate and the Z-shaft plate respectively through the nuts, the X-shaft and the Y-shaft are fixedly connected with the sliders, the sliders slide in the arc-shaped slide grooves of the movable slide channels, when rotated, the ball body can drive the three shafts which are vertical to each other to rotate, and space rotation angles can be timely and accurately decomposed to each vertical shaft. The problem of how a space three-dimensional rotation angle is converted to a plane two-dimensional rotation angle is solved. Angle indexes are arranged on the ball faces on the two sides of the Z-shaft slide groove and the sliders, rotation angles of the ball body relative to the X-shaft plate, the Y-shaft plate and the Z-shaft plate can be read, angle indexes are arranged on the X-shaft plate, the Y-shaft plate and the Z-shaft plate, and rotation angles of the ball body relative to the X-shaft, the Y-shaft and the Z-shaft can be read through the indicators.