Abstract: The coreless linear induction maglev motor (CLIMM) used in ultra-high speed maglev, which may lead to an uneven air-gap between its primary and secondary, is proposed and investigated. The analytical model is set up in 3D cartesian coordinates to calculate the magnetic field and electromagnetic performance. Firstly, the basic structure and principle of the proposed motor is introduced. Then, the 3D magnetic field distribution function and its Fourier series of the primary based on integral approach is proposed. Based on second order vector potential (SOVP), a 3D analytic model of the motor was proposed in the paper, thus, it get the expression of the lift force, thrust force and powerlosses. The calculations of magnetic field in the air gap, forces and powerlosses are conducted by finite element method and analytical method, respectively, the outcome proves that the analytical model in this paper is correct and practical. Finally, a small scale prototype is manufactured, and experiments are carried out to verify the predicted results.