In this study, we investigate the X-ray properties of WISE J090924.01+000211.1 (WISEJ0909+0002), an extremely luminous infrared (IR) galaxy (ELIRG) at $z_{rm spec}$= 1.871 in the eROSITA final equatorial depth survey (eFEDS). WISEJ0909+0002 is a WISE 22 $mu$m source, located in the GAMA-09 field, detected by eROSITA during the performance and verification phase. The corresponding optical spectrum indicates that this object is a type-1 active galactic nucleus (AGN). Observations from eROSITA combined with Chandra and XMM-Newton archival data indicate a very luminous ($L$ (2--10 keV) = ($2.1 pm 0.2) times 10^{45}$ erg s$^{-1}$) unobscured AGN with a power-law photon index of $Gamma$ = 1.73$_{-0.15}^{+0.16}$, and an absorption hydrogen column density of $log,(N_{rm H}/{rm cm}^{-2}) < 21.0$. The IR luminosity was estimated to be $L_{rm IR}$ = (1.79 $pm$ 0.09) $times 10^{14}, L_{odot}$ from spectral energy distribution modeling based on 22 photometric data (X-ray to far-IR) with X-CIGALE, which confirmed that WISEJ0909+0002 is an ELIRG. A remarkably high $L_{rm IR}$ despite very low $N_{rm H}$ would indicate that we are witnessing a short-lived phase in which hydrogen gas along the line of sight is blown outwards, whereas warm and hot dust heated by AGNs still exist. As a consequence of eROSITA all-sky survey, $6.8_{-5.6}^{+16}times 10^2$ such X-ray bright ELIRGs are expected to be discovered in the entire extragalactic sky ($|b| > 10^circ$). This can potentially be the key population to constrain the bright-end of IR luminosity functions.
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