Based on spin-flip model (SFM), the impacts of mismatched intrinsic parameter on leader-laggard chaos synchronization between two mutually coupled verticalcavity surface-emitting lasers (VCSELs) have been investigated numerically. Results show that, for two VCSELs with identical intrinsic parameter, the switching point of leader-laggard caused by continually varying frequency detuning or injection rate detuning is located at zero frequency detuning or zero injection rate detuning, which indicates that the VCSEL with higher frequency or subject to lower injection level plays a leader role. However, for two VCSELs with mismatched intrinsic parameter, the switched point of leader-laggard will deviate from zero frequency detuning or zero injection rate. Therefore, compared with the results obtained under matched intrinsic parameter, the opposite results have been observed in the range between zero detuning and switching point. Additionally, the offsets of switching point induced by different intrinsic parameters are different, and the influence of line-width enhancement factor is found to be the most significant.