Noninvasive blood glucose monitoring technology has advantages of painlessness, no infection, and continuous detection, which is an important direction for the development of blood glucose monitoring technology. In order to explore the effects of frequency and glucose concentration on the dielectric properties, the dielectric-frequency characteristics of aqueous solutions with different glucose concentrations are investigated in the frequency range of 500 kHz to 5 MHz. The results show that when the glucose concentration is constant, the real and imaginary parts of the complex permittivity of the aqueous solution decrease in this frequency band as the frequency increases. When the frequency is constant, the real and imaginary parts of the complex permittivity of the aqueous solution decrease as the glucose concentration increases. The results are different from that in high frequency. In addition, the second-order Debye model fitting of the complex permittivity of aqueous solution and the quadratic polynomial fitting of the parameters in the Debye model are studied in this paper. The determination coefficient of all fitting is higher than 0.93, indicating that the model can better represent the dielectric-frequency response characteristics of glucose solution with different concentrations. Finally, a noninvasive blood glucose monitoring model which consists of skin, blood and muscle, was established and the simulation was carried out through finite-difference time-domain. The results indicate that the voltage difference between receiving electrode 2 and 3 increases linearly with the increasing of glucose concentration. We therefore suggest that the proposed frequency between 500 kHz and 5 MHz is feasible in the applications of noninvasive blood glucose monitoring.