The formulas of polymer melt velocity, shearing rate, and shearing stress under vibration force field are established through simplifying coaxial cylinder circular flow into plane motional flow. On the basis of the concept of energy ratio model, the rate of energy dissipation and the energy ratio about blending systems are expressed, and the affected factors on phase morphology are studied theoretically. The calculated and analytical results of dynamic flow field and energy ratio show that with the increasing of vibration strength, the fluctuating shearing force field exerted on polymer melt and the negative pressure diffusion behavior of instantaneous impulse strengthen. The energy consumption for phase inversion of immiscible polymer blends under vibration force field is less than that of steady state. The parameter controllability of vibration force field provides a more effective method for realizing phase inversion of immiscible polymer blends. The analysis of transmission electron microcopy micrographs of ethylene-propylene-diene terpolymer/polypropylene blends verifies that the energy ratio model and its phase morphology controlling theory have a good coincidence in comparison with experimental results. (c) 2006 Wiley Periodicals, Inc.