This study investigated the creep performance, fracture characteristics, and creep mechanisms of the nickel-base single crystal superalloy DD406 under conditions of 1100°C and 140MPa. The results indicate that the alloy exhibited a creep life of 104.5 hours and a strain of 33.58%. The creep curve exhibited three distinct stages: initial (deceleration), steady-state, and accelerated creep. The fracture surface was characterized by dimples and tearing edges, with no apparent slip planes. Internal to the fracture, oxidation products and recrystallized structures were observed, and the internal pores exhibited elongated shapes oriented perpendicular to the stress axis. Furthermore, analysis of the creep rate-time curve revealed three sub-stages within the initial (deceleration) creep stage, where the creep rate decreased initially, followed by an increase and subsequent decrease with time.