Abstract: Low cycle fatigue tests were conducted on 80SH steel for thermal recovery well casing at 20, 120, 250, 350, 450℃ and strain amplitudes of 0.5%, 0.7%, 1.0%, 1.5%, 2.0%. The low cycle fatigue behavior under the influence of dynamic strain aging (DSA) was studied. Based on low cycle fatigue test data, the relation model between low cycle fatigue life and strain amplitude under the influence of DSA was established. The results show that 80SH steel had significant DSA characteristics at 350℃; the significant secondary hardening behavior of 80SH steel during high temperature low cycle fatigue appeared, resulting in dislocation accumulation in grains which prevented crack propagation; then cyclic hardening occurred, resulting in cleavage steps and a large number of secondary cracks appeared in the low cycle fatigue fracture. In the DSA significant temperature range, fatigue life had bilinear relationship with elastic strain in the double logarithmic coordinate system, while had linear relationship with plastic strain. The superposition of Manson-Coffin linear model and Basquin bilinear model could better describe the relation between fatigue life and strain of 80SH steel under the influence of DSA.