Although the homotopy-knot theory has been utilized to implement effective topological classification for non-Hermitian systems, more profound physical implications underlying distinct knot or link topologies are yet to be fully elucidated. In this work, we propose a one-dimensional non-Hermitian four-band lattice model and map out its phase diagram according to the distinct link structures residing in the momentum space. The topological phase diagram is ascertained through a spectral winding number. Furthermore, we derive the exact analytic formula for the phase boundaries that delineate different link topologies. To explore the concrete physical implications of distinct link topologies, we investigate the many-body ground-state entanglement entropy for free fermions loaded on such non-Hermitian lattice in real space. It turns out that different link topologies imply different magnitudes of entanglement. Moreover, we show that the central charge $c$ extracted from systematic finite-size scaling of entanglement entropy provides effective description of the phase diagram of the link topology. Finally, we further confirm the phase boundaries for the topological phase transitions alternatively by numerical calculations of the many-body ground-state fidelity susceptibility. Our results showcase the direct connection between link topology and observable entanglement properties of non-Hermitian systems, offering a novel experimental route to characterize link topological phases via measurable quantum correlations. This work not only bridges the gap between abstract topological classification and real-space physical phenomena but also paves the way for engineering non-Hermitian topological systems with tailored entanglement, with potential implications for topological quantum information processing.

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• Entanglement entropy
• Geometric & topological phases
• Quantum entanglement
• Non-Hermitian systems
• Topology