The invention discloses a sensing element with adjustable positions and magnetic fluxes of magnetic blocks in a shell, and belongs to a technology for providing a control signal by multi-point magnetic induction. Permanent magnet blocks and halls are arranged inside a rotating plate and a fixing plate; a plurality of permanent magnet blocks which are distributed in a ring are fixedly arranged on the rotating plate; the distances between the permanent magnet blocks can be adjusted and the magnetic fluxes of the permanent magnet blocks at different positions can be adjusted; the magnetic polarities of the adjacent permanent magnet blocks are opposite at one side of the rotating plate, namely the magnetic polarity distribution mode of all permanent magnet blocks at one side of the rotating plate is an N pole, an S pole, the N pole ...; and halls on the fixing plate are arranged at the positions near the permanent magnet blocks. The sensing element has the advantages that the halls can obtain rectangular wave signals by an opposite distribution mode of the magnetic polarities NS of the adjacent permanent magnet blocks; the signals can be conveniently subjected to digital treatment; the rectangular wave signals can present the positions of the permanent magnet blocks on the rotating plate by differences of the distances and the magnetic fluxes; uses of different rectangular waves are determined; the opposite positions of the permanent magnet blocks and the halls are fixed; and signal output is reliable.