Based on the I-type quantum well of the GaSb system, lasers with a lasing wavelength of 2。75 μm was fabricated. The valence band level of the barrier was effectively reduced, and the valence band order was increased using the quinary barrier material AlGaInAsSb. Additionally, the luminescence wavelength of the quantum well red shifted to 2。75-μm band. The optimal epitaxial parameters of the quantum well were obtained by optimizing the growth parameters of molecular beam epitaxy, and a Fabry-Perot laser device with a cavity length of 1。5 mm, ridge width of 50 μm, and central wavelength of 2。75 μm was fabricated. The laser realizes continuous lasing at room temperature, and its maximum output power and threshold current are 60 mW and 533 A·cm -2, respectively.