Gate control ability is expected to keep constant, guaranteeing accurate MOSFET adjustment of drive strength by changing its size. In NCFET, the non-uniform distribution of ferroelectric polarization and capacitance match are sensitive to the size and tend to enhance the fluctuation of gate control. In the current work, a detailed simulation was made on NC-FinFET to clarify the effect of structural factors on its gate control. These factors include the Fin structure (length, width, and height), the doping concentration in the GaAs channel, and ferroelectric film thickness. Simulation results indicate that the SS of NC-FinFET with BTFM-CTO film is more insensitive to the variation of structural factors than that with HfO2 or PZT film. Thus, the fluctuation of gate control can be significantly weakened with a suitable set of structure factors and ferroelectric parameters. The current work generates new insights into the fluctuation of gate control with varying structure factors and adjustment of NC-FinFET drive strength, which are essential for NC-FinFET to applicate in an analog circuit.