  We systematically investigate the properties of three-dimensional dipolar
binary Bose mixture at low temperatures. A set of coupled self-consistent
equations of motion are derived for the two condensates. In the homogeneous
case, useful analytical formulas for the condensate depletion, the anomalous
density, the ground-state energy, and the equation of state are obtained. The
theory is extended to the inhomogeneous case and the importance of the
inhomogeneity is highlighted. Our results open up a new avenue for studying
dipolar mixture droplets. Impacts of the dipole-dipole interaction on the
stability, density profiles, and the size of the self-bound droplet are deeply
discussed. The finite-temperature behavior of such a state is also examined.
