The traditional electromagnetic suction levitation adopts air gap feedback to realize closed-loop control, while the air gap sensor has the disadvantages of large volume, high cost and complex installation. An electromagnetic suction levitation method is proposed, in which the air gap is observed by magnetic field and current, and the observed air gap is used for closed-loop feedback. The functional relationship between air gap, magnetic field and current is studied by theoretical analysis and simulation. The position of magnetic field measuring point is designed and analyzed. The measured data show that the observed air gap under the proposed electromagnetic suction levitation method is consistent with the measured air gap, so it can be used for closed-loop feedback. The influence of observation fitting coefficient on the stability of closed-loop system is analyzed theoretically. Finally, the stable levitation at 7 mm is realized in experiment.