Abstract: This paper introduces the structural design of the compact high speed electric spindle. Finite element model of the double rotor system of the spindle-sliding mechanism is established. The static and dynamic characteristics of the dual-rotor system are studied. The static displacement, mode shape, natural frequency and response displacement under the working condition are obtained. The parameters of spindle-sliding material, bearing pre-tightening force, bearing group span, spindle-slider contact stiffness and spindle-shank contact stiffness are optimized. The results show that the static and dynamic stiffness of the electric spindle meets the requirements after optimization. The natural frequency has been improved. The research provides a theoretical basis for the design of compact high-speed electric spindles.