In this work, we propose a new scheme of a photonic device containing a layer of black phosphorus, an electrically controlled nematic liquid crystal (LC) and a distributed Bragg reflector (DBR). We have studied the influence of the electron carrier density in the black phosphorus layer, as well as the thickness of the defect layer, and also the reorientation of the LC director on the reflection spectrum of the device in the THz spectral range. It is shown how a change in these parameters affects the reflection spectra of the device. Such device can be used, for example, as tunable phase shifter, modulator and absorber of electromagnetic radiation.