The invention relates to a control method and device of an intelligent magnetic suspension electric spindle, and belongs to the technical field of electric spindle control. The device comprises a controller, a non-linear power amplifier and an outer circuit module; the non-linear power amplifier comprises a digital curve cluster tracing module, a non-linear digital compensation module, an output signal converter module, a non-liner compensation database module, a compensation parameter determining module, a material parameter module, an output circuit module, an input connector module and a position signal module; the outer circuit module comprises a rotating shaft, a differential type electromagnetic coil and a sensor module; the self-adaptation slide form control algorithm is adopted in the controller, according to rotating shaft displacement signals detected by an eddy-current transducer, through non-linear digital compensation, non-linear factors of the system are filtered out, and the system is linear; a differential type electromagnet is of a differential structure with an upper coil and a lower coil, and the current generated in the two coils is used for controlling.