The SLIM has been widely applied in transportation for its simple-firm structure and its directly forward electromagnetic thrust. Because of its discontinuous magnetic circuit, the motor has transverse and longitudinal end effects. There are eddy currents, which become greater as motor spread increases, occurring in both entrance and exit of its secondary side for magnetic flux balance. End effects and eddy currents bring ill impact to air gap magnetic flux which reduce its available magnetic flux of air gap and pull coefficient. This paper describes particular discussions on the SLIM working characters and works out the d-q axis equivalent circuits. The changes of mutual inductance and resistance in d axis indicate both the second longitudinal end effect and the eddy current influences. Then the article establishes SLIM control equations connected with the rotor-flux oriented(RFO)vector control theory in rotary motor. The paper brings forward uds, uqs, iqs online decouple compensation based on the rotor magnetic flux, speed, current regulators, which adjust and accommodate pulsive force, d-q axis voltages, d-q magnetic fluxes, d axis mutual inductance. The result indicates that this method reduces the torque ripple and makes the stator currents flat, speed smooth during the sudden change in motor speed of no load, which provides theory guidance to the SLIM application analysis and achieves some active effects.