  Be/$\gamma$-ray binaries comprise a confirmed or presumptive pulsar orbiting
a Be star and emit luminous $\gamma$-rays. Non-thermal emissions are thought to
arise from synchrotron radiation and inverse-Compton (IC) scattering in the
shock where the pulsar wind is terminated by the stellar outflow. We study wind
interactions and shock radiations from such systems and show that the bimodal
structures observed in keV/TeV light curves are caused by enhanced synchrotron
radiation and IC scattering during disc passages. We use a simple radiation
model to reproduce orbital modulations of keV X-ray and TeV $\gamma$-ray flux
and compare with two confirmed pulsar/Be star binaries (i.e. PSR B1259-63/LS
2883 and PSR J2032+4127/MT91 213), and two candidates (i.e. HESS J0632+057 and
LS I +61$^{\circ}$303). We find that the keV/TeV light curves of the former two
binaries can be well explained by the inclined disc model, while modelling the
modulated emissions of the latter two sources remains challenging with current
orbital solutions. Therefore, we propose alternative orbital geometries for
HESS J0632+057 and LS I +61$^{\circ}$303. We estimate the positions and
inclination angles of Be discs by fitting correlated keV/TeV light curves. Our
results could be beneficial for future measurements of orbital parameters and
searches for radio pulsations from presumed pulsars.
