<p>Frustrated magnetic systems with anisotropic exchange interactions have been recognized as key platforms for discovering exotic quantum states and quasiparticles. In this study, we report the pressure evolution of magnetic structures and quasiparticle excitations in the frustrated semiconductor YbCuS₂, characterized by Yb³⁺ zigzag chains with competing exchange interactions. At ambient pressure, YbCuS₂ exhibits a magnetic transition at <i>T</i>_N~0.95 K, forming an incommensurate helical magnetic order. Under hydrostatic pressure of 1.6 GPa, <i>T</i>_N increases to 1.17 K, and the magnetic structure changes to a commensurate one, which can be regarded as an odd-parity magnetic multipole order. Remarkably, pressure suppresses the gapless quasiparticle excitations. These findings suggest that pressure alters the exchange interactions between the Yb ions, affecting both the magnetic ground state and the quasiparticle excitations. Our results highlight the pivotal role of anisotropic interactions in one-dimensionality to stabilize the complex quantum phases, offering insights into the interplay among frustration, dimensionality, multipoles and emergent quasiparticles.</p>