The invention discloses a constructing method of a nerval net generalized inversing bearingless permanent magnet synchronous motor decoupling controlling device, which takes two Clark inverse transformations, two electric current tracing type inverters, a bearingless permanent magnet and a load model as a whole to form a composite controlled object, a nerval net generalized inverse of the composite controlled object is formed through adopting static nerval net added with a plurality of linear links, then the nerval net generalized inverse is reversely arranged before the composite controlled object to form a generalized pseudolinear system, the generalized pseudolinear system is decoupled to three single input and output subsystems through linearization, finally a nerval net generalized inverse, the two Clark inverse transformations and the two electric current tracing type inverters are all formed to a nerval net generalized inversing bearingless permanent magnet synchronous motor controlling device, the controlling device can not only realize dynamic decoupling between a radial position system of a motor and torque moment system and between radial forces, but also be taken as a nonlinear open-cycle controlling device to use directly, and stable suspension and operation of a rotor of a motor can be ensured.