The vibration problem of the electric pump lifting string in ultra-deep wells under complex working conditions seriously affects the safety and operation efficiency of the lifting system. Aiming at the longitudinal, transverse and torsional vibration problems caused by the electric pump excitation, fluid load and temperature effect, a dynamic model of the longitudinal-transverse-torsional vibration of the ultra-deep well electric pump lifting string considering the fluid-solid coupling, temperature effect and the rotation excitation of the submersible electric pump is established. The influence of string size, fluid viscosity and electric pump speed on the vibration characteristics of the string is systematically analyzed by using the finite element analysis numerical solution method. The results show that the longitudinal vibration of the pipe string is mainly affected by the self-weight and increases with the depth. The lateral vibration increases slightly along the well depth, and increases exponentially in the deep area of the middle. The torsion angle of the string accumulates with depth. The research results provide a theoretical basis for the optimal design of the electric pump lifting system in ultra-deep wells.