The invention discloses a vector control AC frequency-variable speed regulation system of an electric automobile, which comprises a DSP controller, a reverse rotation converter module, a two-phase/three-phase AC converter module, a PWM converter, a three-phase AC induction motor, a magnetic flux linkage observer, and a battery pack; wherein, a control system conducts the control by means of speed and magnetic flux linkage closed loop, and a magnetic flux observer uses a current structure; the amplitude and phase of the magnetic flux of a rotor are solved by using three-phase stator current and the rotation speed of the motor, and the field orientation is realized; as the asynchronous motor is a nonlinear link coupled by multiple variables, decoupling and linearization can be achieved via the filed orientation, and therefore system calibration can be performed to obtain the desired dynamic performance. Therefore, by means of comparative and comprehensive researched into the direct torque control technology and vector control technology, the vector control AC frequency-variable speed regulation system has the advantages of solving the key technical problems of the frequency-variable speed regulation of the driving system of an electric automobile, and providing a more efficient technology for the driving system of the electric automobile.