The InAsSb device with nBn structure has many advantages, such as low diffusion current limit, low cost, easy realization of large array, compatibility with existing III-V diode circuit and so on. It is one of the first choices for medium and long wave miniaturized detector with low power consumption, low cost and high resolution detector. In the process of InAsSb epitaxial growth, it is difficult to accurately control the composition of As. In order to find the allowable error range, the influence of As component on the surface morphology, lattice quality and cut-off wavelength of InAsSb material is studied. The experimental results show that under the premise that the epitaxial thickness of the material is less than the critical thickness, the material has a higher tolerance for compressive stress than tensile stress. Controlling the As component within the range of slightly less than 91% can not only ensure the quality of the material, but also slightly increase the response wavelength of the device.