To improve the reception performance of weak quadrature phase-shift keying（QPSK）modulated signals and surpass the standard quantum limit（SQL）, this paper proposes a photon-number-resolving（PNR）quantum-enhanced receiver scheme based on a fiber storage ring. By integrating single-photon detectors（SPDs）with a fiber storage ring structure, the scheme achieves efficient photon-number-resolving capability. Adaptive feedback control and Bayesian probability updates dynamically optimize the displacement operator, significantly reducing system complexity and implementation costs. Simulation results demonstrate that when the average photon number |α|²≥1.5, the symbol error rate of this scheme breaks the SQL, showing approximately a 10% reduction compared to traditional SPD schemes. Particularly under weak coherent states（|α|²<2）, the storage ring structure exhibits higher measurement accuracy and lower error rate.