The invention discloses a guiding and positioning device used for aerial docking of a fan impeller assembly and a cabin. The guiding and positioning device comprises a first arc-shaped supporting plate and a second arc-shaped supporting plate, a plurality of baffles, a plurality of hydraulic positioning mechanisms, a plurality of supporting blocks, a plurality of rotating mechanisms, and a plurality of hydraulic guiding mechanisms, wherein the first arc-shaped supporting plate and the second arc-shaped supporting plate are hinged together, and an annular plane is defined by the first arc-shaped supporting plate and the second arc-shaped supporting plate; the baffles are evenly hinged to the annular plane in the circumferential direction, and the inner side faces of the baffles are planes;one end of each hydraulic positioning mechanism is hinged to the annular plane, the other end of each hydraulic positioning mechanism is hinged to the outer side of the corresponding baffle, and the hydraulic positioning mechanisms are used for driving the baffles to open or close; the supporting blocks are evenly arranged in the annular plane in the circumferential direction; the rotating mechanisms are evenly arranged on the annular plane in the circumferential direction and are close to the supporting blocks, an output shaft of each rotating mechanism is fixedly connected with one axial endof the corresponding supporting block, and the rotating mechanisms are used for driving the supporting blocks to rotate around the output shafts; and the hydraulic guiding mechanisms are in one-to-one correspondence with the supporting blocks, one end of each hydraulic guiding mechanism is perpendicularly connected with the other end of the corresponding supporting block, an electromagnet is arranged at the other end of each hydraulic guiding mechanism, and the hydraulic guiding mechanisms are used for guiding the fan impeller assembly.