  In this paper we study the behavior of the multi-field in phantom inflation,
when massive scalar fields work collectively, in which the scale factor is a
power law. We evaluate its parameter values by applying certain constraints on
our model parameters, and we investigate that before the Big Rip singularity
occurs the universe is in phantom inflationary phase. Furthermore, we calculate
these values for this period then compare with current observations of CMB, BAO
and observational Hubble data. We find that results may be consistent with
observations. This implies that in the dark-energy equation of state (EOS)
parameter $\omega_{DE}$ at the Big Rip remains finite, with the divergence of
pressure and dark energy density.
