  Hard X-rays above 10 keV are detected from several anomalous X-ray pulsars
(AXPs) and soft gamma-ray repeaters (SGRs), and different models have been
proposed to explain the physical origin within the frame of either magnetar
model or fallback disk system. Using data from $\it Suzaku$ and INTEGRAL, we
study the soft and hard X-ray spectra of four AXPs/SGRs, 1RXS J170849-400910,
1E 1547.0-5408, SGR 1806-20 and SGR 0501+4516. It is found that the spectra
could be well reproduced by bulk-motion Comptonization (BMC) process as was
first suggested by Tr$\"u$mper et al., showing that the accretion scenario
could be compatible with X-ray emission of AXPs/SGRs. HXMT simulations for BMC
model show that the spectra would have discrepancies from power-law, especially
the cutoff at $\sim$ 200 keV. Thus future observations are promising to
distinguish different models for the hard tail and may help us understand the
nature of AXPs/SGRs.
