To optimize the process of hot rolling for nickel-section austenitic stainless steel with large deformation, the isothermal hot compression tests of 1Cr14Mn10Ni1.5 stainless steel were carried out on Gleeble-3500 thermal simulation system at temperatures of 950 - 1250℃, strain rates of 0.01-5.0 s-1, and strains of 0.36, 0.69 and 0.92. The 3D hot processing maps were established based on the strain effect. The thermal activation energies under three strains were calculated by using the Arrhenius type constitutive equation. The evolution behavior of the hot processing map under the strain effect was analyzed by combining it with the microstructure. The results show that when the true strain increases from 0.36 to 0.69 and 0.92, the thermal activation energy Q decreases respectively from 501kJ/mol to 427kJ/mol and 424.86kJ/mol, indicating that the rate of dislocation multiplication and generation is lower than the rate of dislocation movement and annihilation in the strain range of 0.36-0.69. The hot processing map shows that the peak and valley regions change with the increasing strain, mainly in the direction of low temperature and high speed, which is caused by the increase of the total energy of strain input. There are three peak regions in the hot processing map of the experimental steel, only 0.69 strain, under the conditions of 1175-1225℃, 1.0-5.0 s-1 can reach the maximum processing efficiency of 38%, which is related to the temperature rise at high speed. As the strain increases to 0.69 and 0.92, the instability region extends first and then shrinks. The stress-strain curves and microstructure show that the softening mechanism of the high efficiency region is dynamic recrystallization(DRX), while the unstable region is characterized by discontinuous dynamic recrystallization(DDRX) and dynamic recovery(DRV).