Ternary GaAsSb nanowires (NWs) have shown considerable potential in the applications of infrared optical nanodevices due to their direct bandgap and wavelength-tunable light emission which covers the range from 870 nm to 1700 nm by changing the content of Sb in GaAsSb NWs. Due to the high surface state density, the light emission efficiency of GaAsSb NWs is quite low and the light emission is difficult to observe under room-temperature conditions. The previous studies about the optical properties of GaAsSb NWs were mainly carried out under low-temperature conditions, which has limited their room-temperature optical properties modulation study and room-temperature application. In the present study, we realize optical properties modulation of GaAsSb NWs under room-temperature conditions through the high-pressure strategy, using both photoluminescence (PL) and Raman spectroscopy methods. With increasing the pressure, the PL intensity of GaAsSb NWs presents an obvious enhancement at room temperature and the PL peak position presents a blue-shifted trend. With varying the wavelength (473 nm, 514 nm, and 633nm) of the incident laser, the excitation-wavelength-dependent PL can be observed in GaAsSb NWs. The laser with a longer wavelength (633 nm) will excite the stronger light emission. The Raman spectra of GaAsSb NWs excited by varied lasers (473 nm, 514 nm, and 633 nm) both showed blue shift under compression. We selected four pressure points (0.7 GPa, 1.2 GPa, 1.8 GPa, and 2.5 GPa) for the detailed comparison between the Raman spectra excited by different lasers. Under the excitation of 473 nm laser, the Raman peaks of GaAsSb NWs present evident red-shift compared to those excited by 514 nm or 633 nm laser, which reveals the existence of temperature difference. The relative temperature difference in GaAsSb NWs induced by two different lasers (473 nm and 633 nm) could be estimated up to 200 K. The laser with shorter wavelength will induce a stronger heating effect in GaAsSb NWs and reduce the light-emission efficiency. Under high-pressure condition, the charge transfer between the surface of GaAsSb NWs and pressure transmitting medium can be enhanced, which results in the reduction of surface state density and laser-heating effect. Therefore, the high-pressure strategy provides an efficient route to suppress the high surface state density and optimize optical properties of semiconductor nanostructures.