Iron-based superconductors (FeSCs) have been an essential research area in condensed matter physics. Spins of iron sites forming a long periodic configuration, called the magnetic order, has been found strongly related to the superconducting phase in FeSCs. The superconducting phase typically appears when the magnetic order is suppressed by applying pressure or doping carriers. The majority of the systems exhibit the same two-dimensional iron square lattice. The discovery of pressure-induced superconductivity in quasi-one-dimensional ladder compounds BaFe2X3 (X=Se,S) introduces a novel structural prototype for unconventional superconductivity. This work is aimed to investigate the magnetic order in the pressure-temperature phase diagram to understand the interplay between the magnetism and the superconductivity under the pressure by neutron diffraction technique.