Mid-to-near-infrared spectral translation plays an important role in various applications in mid-infrared spectral range. However, the conversion efficiency and spectral tuning range were usually limited by the large frequency detuning between the pump and mid-infrared signal. In this work, a As₂Se₃ chalcogenide waveguide was proposed to fulfill phase matching condition in four-wave mixing with large pump-signal frequency detuning. The waveguide geometry was optimized through dispersion engineering to provide normal group velocity dispersion and negative fourth-order dispersion around 2 μm. The mid-to-near-infrared spectral translation with high efficiency and wide-band tunability was facilitated. By using a pump wavelength in the normal dispersion regime, the spectral translation and parametric amplification of mid-infrared signal ranging from 2.7 to 6.2 μm is obtained. The proposed waveguide has great potentials in high-sensitivity detection of mid-infrared signals and widely tunable mid-infrared generation.