In this paper, for the first time, the dynamic characteristics of optical injection locking vertical cavity surface emitting laser (OIL-QD-VCSEL) are investigated theoretically. By using the rate equations for dynamics of electrons and holes at GaAs barrier, wetting layer (WL), and three discrete QD levels and the heat equation, turn-on dynamics and also the small and large signal responses of laser without optical injection are numerically simulated. By adding the equations for the amplitude and phase of the QD-VCSEL field to the system of equations, the dynamic characteristics of optical injected laser are calculated. It is shown that due to optical injection, the electron and hole dynamics in QDs are synchronized, the modulation frequency is enhanced, the chirp is significantly reduced and QD-VCSEL manifests a high performance at the repetition frequency more than relaxation oscillation frequency (about 22 GHz).