  In the recent years, the field of fast radio bursts (FRBs) is thriving and
growing rapidly. It is of interest to study cosmology by using FRBs with known
redshifts. In the present work, we try to test the possible cosmic anisotropy
with the simulated FRBs. In particular, we only consider the possible dipole in
FRBs, rather than the cosmic anisotropy in general, while the analysis is only
concerned with finding the rough number of necessary data points to distinguish
a dipole from a monopole structure through simulations. Noting that there is no
a large sample of actual data of FRBs with known redshifts by now, simulations
are necessary to this end. We find that at least 2800, 190, 100 FRBs are
competent to find the cosmic dipole with amplitude 0.01, 0.03, 0.05,
respectively. Unfortunately, even 10000 FRBs are not competent to find the tiny
cosmic dipole with amplitude of ${\cal O}(10^{-3})$. On the other hand, at
least 20 FRBs with known redshifts are competent to find the cosmic dipole with
amplitude 0.1. We expect that such a big cosmic dipole could be ruled out by
using only a few tens of FRBs with known redshifts in the near future.
