We show the control of optical bistability and multistability via the atomic coherence induced by the microwave field in the presence of the antirotating wave coupling. Appearance or disappearance of bistability and multistability， manipulation of the hysteresis hoop widths and the threshold intensity are achieved by changing the initial phase of the microwave field. Physically， the rotating wave and antirotating wave couplings can be treated as the equivalent bichromatic excitation. Each of the coupled levels are split into an infinite set of sublevels. As a consequence， each of the bare state transitions is split into an infinite set of transitions of different frequencies. The coherent superposition of these split transitions， which depends on the initial phase of the microwave field， determines the nonlinear absorption and dispersion of the medium.