The invention provides a three-phase current reconstruction method using single sampling resistance. The method includes the following steps: A, sampling direct-current bus current of a frequency converter; B, estimating three-phase current and counter electromotive force of an induction motor by using a state observer; C, judging whether current reconstruction is needed according to action time of effective vectors, if yes, carrying out a step D, and if not, skipping to a step G; D, observing motor current in an abnormal sampling area of the three-phase current by using the state observer; E, carrying out error control on the observed motor current; F, carrying out amplitude limiting processing on the variable quantity of the observed motor current; G, generating space vector pulse width modulation (SVPWM) signals; and H, setting time for the next time of direct-current bus current sampling, interrupting the process, and returning to the step A. According to the three-phase current reconstruction method using the single sampling resistance, accuracy and generality of current estimation are improved, the wide-range current reconstruction with various SVPWM models is precisely achieved, SVPWM voltage basic vectors are not changed, and voltage vector total harmonic distortion (THD) values are significantly reduced.