The invention discloses a precise positioning device of relative spatial positions and rotation angles of two parallel cylinders. The device comprises a rotary table, a reciprocating linear sliding table module, a first reciprocating linear sliding table sliding rod, a second reciprocating linear sliding table sliding rod, a forward lead screw, an inverse lead screw, a first reciprocating linear sliding table, a second reciprocating liner sliding table, a first sliding table connection plate, a second sliding table connection plate, a rotary dial, a locking knob, a first rotary sliding table, a second rotary sliding table, a first cylinder fixing base and a second cylinder fixing base. The precise positioning device provides a more reliable operation mode for more precise, more efficient, convenient and quick control of the center distance of the two cylinders, precise adjustment of relative positions of serial arrangement, parallel arrangement and staggered arrangement and angles of the cylinders around the center axes of the cylinders, and the situation that relative positions and the angles of two workpieces are precisely adjusted in related cylinder fluid-solid coupling experiment research and other manufacturing links.