Abstract: A short process of Inconel 625 alloy tube was developed to solve the problems of the traditional extrusion process, and particular attention was paid on the hot deformation behavior of the as-cast Inconel 625 alloy. The hot compression experiments were performed to study the hot deformation behavior of Inconel 625 in the temperature range of 900–1200 °C and strain rate range of 0.01–10.00 s−1 by Gleeble-3500. The hot compressed microstructure was examined to study the effects of temperature and strain rate on the microstructural characteristic by electron backscatter diffraction (EBSD). The results show that the processing maps were greatly influenced by the temperature rather than the strain rate. It is found that with the strain increasing, the instability zone gradually turned to the low-temperature and low strain rate area, while the range of high-temperature instability area shrank. The optimum condition of the as-cast Inconel 625 alloy was determined as high strain rate region (temperature of 1100–1200 °C, strain rate of 1.00–10.00 s−1) with the dissipation efficiency of above 0.28. As illustrated by microstructural characteristic of EBSD analysis, the perfect dynamic recrystallization occurred and fine grain structure was obtained under this deformation conditions. Graphic abstract: The hot processing map and microstructure evolution of as-cast Inconel 625 alloy at various temperatures and strain rates.[Figure not available: see fulltext.] © 2020, The Nonferrous Metals Society of China and Springer-Verlag GmbH Germany, part of Springer Nature.