The performance of uncooled heat detectors still needs to be improved in spectral inspection applications.In order to reduce the thermal noise and dark current and realize the high temperature performance of the device,the multiplier layer and the absorption layer are designed separately,and In0.83Al0.17As is used as the multiplication layer material,the effects of different temperature on the dark current and light responsivity of the device are investigated in detail by using the simulation software Silvaco TCAD.The results show that in the range of high temperature 160～300K,the dark current of the device increases with the increase of temperature,and the light responsivity shows a change of increasing and then decreasing.Using the equation,it is further calculated that the device has a dark current density of 0.485 A/cm2 at-500 mV and 300K,a peak responsivity of 1.818 A/W at 1.5μm,a zero bias differential resistance area of 0.053 Ω·cm2,and a specific detectivity of 3.26×109cm·Hz 1/2·W -1.