In this paper, the hot deformation behavior of IN783 low-expansion superalloy was investigated through hot compression experiments at the deformation temperatures of 1000-1120 ℃ and strain rates of 0.01-10 S^-1. The microstructure evolution of the alloy under different deformation conditions was studied using electron backscatter diffraction (EBSD). The results indicate that the peak stress of IN783 alloy significantly decreases with the increase of deformation temperature and the decrease of strain rates. Combined with Arrhenius equation and Zener Hollomon parameter model, the constitutive equation of the alloy was established, which can well describe the relationship between peak stress, deformation temperature and strain rate during hot deformation of IN783 alloy. The hot working diagram of IN783 alloy was drawn based on the dynamic material model. According to the hot working diagram and the microstructure observation, the instability zone of IN783 superalloy was determined as: deformation temperature of 1095 ℃ - 1120 ℃, strain rate of 100.39814^-101 ^S-1. In addition, under the condition of high temperature and low strain rates (1060-1120 ℃, 0.01 S-1^{), mixed crystal} and grain coarsening would occur, which makes it not suitable for the hot working of IN783 alloy although the alloy has high power dissipation coefficient in those parameters.