  In the paper, we present a detailed discussion on the $\Xi_{cc}$ production
at a fixed target experiment at the LHC (After@LHC). The doubly charmed baryon
$\Xi_{cc}$ is produced via the channel, ${\rm Proton} + {\rm
Proton}\to\Xi_{cc}+X$. In estimating its hadroproduction, we discuss three
dominant subprocesses, e.g. $g+g\to \Xi_{cc} +\bar{c} +\bar{c}$, $g+c\to
\Xi_{cc}+\bar{c}$ and $c+c\to \Xi_{cc}+g$. During the production, it shall
first generate a binding diquark and then form the $\Xi_{cc}$ baryon by
grabbing soft light-quarks or gluons. We observe that both the two diquark
configurations $(cc)[^3S_1]_{\bf\bar 3}$ and $(cc)[^1S_0]_{\bf 6}$ can have
sizable contributions to the $\Xi_{cc}$ production. Large number of $\Xi_{cc}$
events can be generated at the After@LHC, whose total production cross section
is larger than that of the SELEX experiment by about thirty-five times. It may
also possible to study the properties of $\Xi_{bc}$ at the After@LHC. More
specifically, we shall have about $8.3 \times 10^6$ $\Xi_{cc}$ events/year and
$1.8 \times 10^4$ $\Xi_{bc}$ events/year when its integrated luminosity
approaches to $2$ fb$^{-1}$/year. Thus, in addition to SELEX and LHC, the
After@LHC shall provide another useful platform for studying the baryon
properties.
