Analysis and robustness improvement of FCS-MPCC for IPMSM with model parameter mismatches are studied in this paper. The prediction error of the current in synchronous rotation coordinate is analyzed and it is divided into two categories according to whether it is related to the selected optimal voltage vector. A robustness improvement method by extracting the information of both kinds of prediction errors in the last sampling period is proposed. The simulation and experimental results demonstrate that the proposed method can effectively improve the ability to resist multiple model parameter mismatches.