In order to realize the high-performance current tracking control and robustness of T-type three-level active power filter (APF), a no-beat optimization model predictive current control (FCS-MPC) algorithm is proposed and designed. Filter inductor online observer. Firstly, in order to reduce the computational complexity of the rolling optimization process, a simplified method of voltage vector control set based on harmonic current deadbeat prediction is proposed, which reduces the number of iterative calculations in each control cycle. Then, in order to reduce the influence of the inductance parameter mismatch on the performance of the FCS-MPC algorithm, an in-line correction of the parameters of the inductive observer is designed. Finally, the proposed algorithm is verified by simulation. The simulation results show that the proposed algorithm not only maintains the superior dynamic and static response performance of the traditional FCS-MPC, but also significantly reduces the computational complexity of the digital implementation and improves the robustness of the control system when the parameters are mismatched.