Abstract: Aimed at the problem that the medium voltage three-level variable frequency induction motor needs to adjust parameters artificially and overshoot is too large, an adaptive second-order system ADRC algorithm (ASO-ADRC) is proposed. Through the establishment of nonlinear mathematical models about tracking differentiator, extended state observer, and error compensation controller, it was transformed into parameter tuning of bandwidth and compensation coefficient, and the optimal parameter value was calculated by sparrow search algorithm. As the control input of the compensation variable, the second-order system structure was constructed, and the time-related indicators and the maximum overshoot indicators of the three-level frequency conversion were optimized. Experimental results show that the proposed system can adaptively adjust the errors caused by internal and external factors that cannot be compensated for, and can reduce the overshoot.