The invention discloses a rotor position detecting and mounting assembly which comprises a rotary testing sleeve and a plurality of sensor mounting brackets. Radial position sensors and axial positionsensors are mounted on the sensor mounting brackets through bolts in a fastening manner. A position adjusting slide block is arranged between adjacent two sensor mounting brackets. The position adjusting slide block comprises a slide block with a bevel and an adjusting screw connected to the slide block with the bevel through a thread, and a fixed block is arranged between the slide block with the bevel and the adjusting screw; each of left and right side faces of each sensor mounting bracket comprises a slope structure adaptive to the bevel and a plane parallel to the side wall of the fixedblock. The invention also discloses a magnetic suspension bearing. Compared with the prior art, the rotor position detecting and mounting assembly has the beneficial effects that a lot of field timingwork is avoided, and the rotor position detecting and mounting assembly is simple, good in detecting consistence, compact in structure and easy to mount, detach and maintain.