  In the present paper, we make a detailed study on the doubly heavy baryon
photoproduction in the future $e^+e^-$ International Linear Collider (ILC). The
baryons $\Xi_{cc}$, $\Xi_{bc}$, and $\Xi_{bb}$ are produced via the channel
$\gamma \gamma \to \Xi_{QQ'} +\bar{Q'} +\bar{Q}$, where $Q$ and $Q'$ stand for
heavy $c$ or $b$ quark, respectively. As for the $\Xi_{QQ'}$-baryon production,
it shall first generate a $(QQ')[n]$-diquark and then form the final baryon via
fragmentation, where $[n]$ stands for the color- and spin- configurations for
the $(QQ')$-diquark states. According to the non-relativistic QCD theory, four
diquark configurations shall provide sizable contributions to the baryon
production, e.g., $[n]$ equals $[^3S_1]_{\bar{\textbf{3}}}$,
$[^1S_0]_{\textbf{6}}$, $[^3S_1]_{\textbf{6}}$, or
$[^1S_0]_{\bar{\textbf{3}}}$, respectively. We adopt the improved helicity
amplitude approach for the hard scattering amplitude to improve the calculation
efficiency. Total and differential cross sections of those channels, as well as
the theoretical uncertainties, are presented. We show that sizable amounts of
baryon events can be generated at the ILC, i.e., about $2.0\times 10^{6}$
$\Xi_{cc}$, $2.2\times 10^{5}$ $\Xi_{bc}$, as well as $3.0\times
10^{3}\;\Xi_{bb}$ events are to be generated in one operation year for
$\sqrt{S}=500$ GeV and ${\cal L}\simeq 10^{36}$cm$^{-2}$s$^{-1}$.
