Abstract: The spectral responsivity calibration of photodetectors is of great significance for their widespread applications. However, in near-infrared band, particularly within the range of （1600~2300）nm, conventional photodetectors were found to suffer from small photosensitive areas (Φ≤3 mm) and non-uniform spatial response, which severely hindered high-precision spectral responsivity calibration. To address this issue, a novel extended InGaAs standard detector was designed and developed presented, and its spectral responsivity calibration was successfully realized. First, the influence of integrating sphere structure on detector's response uniformity was investigated through numerical simulations. Subsequently, based on simulation results, both an integrating-sphere-coupled single detector and a dual-detector configuration were fabricated, and a corresponding uniformity measurement setup was established. The measured uniformity results were 0.4% (single detector) and 0.2% (dual-detector), which were consistent with the simulation results. Furthermore, a spectral responsivity calibration system based on a pyroelectric power meter was constructed for integrating-sphere-coupled dual detector, and the spectral responsivity calibration was successfully performed over （1600~2300）nm wavelength range. Through the design and experimental validation of integrating-sphere-extended InGaAs detector, the challenge of lacking standard photodetectors in near-infrared band is effectively resolved.