The surface of as-cast columnar crystal DZ125 alloy was blew sand then heat treatment by the standard heat treatment process obtained the recrystallization with different thickness, and the creep life of the alloy was measured. The effect of recrystallization and its thickness on the creep properties of the alloy was analyzed. The microstructure of the alloy was observed by scanning electron microscope. The experimental results show that the thickness of recrystallization on the surface is different from alloys at varied sand blowing intensity after heat treatment, with the sand blowing intensity increase the thickness increase of the columnar crystal DZ125 alloy. The carbide in the as cast DZ125 columnar crystal alloy is slice, strip or grain, and the carbide after the standard heat treated alloy is dissolved, the size of the slice is reduced, and the surface of slice carbide appears holes. Strip carbides turn into grain, the original grain size reduction. A small amount of grain carbides are precipitated around the grain boundaries after recrystallization. The creep life of 2mm and 4mm sample with different recrystallization thickness is roughly equal under the 980℃ and 235MPa conditions. Compared to the non-occurrence the recrystallization of columnar crystal alloy, the life of the DZ125 alloy was decreased by 30%. During the creep, the carbides in the grain are accumulated and grow around the grain boundary, which is beneficial to improve the strength of grain boundary. During creep the crack initiation is mainly along with the recrystallization grain boundary which vertical the stress axis. Crack initiation points are also existed in the internal of the columnar crystal alloy. The γ′ phase rafted in recrystallization grains indicate that the grain boundaries of recrystallization which weakening the creep strength of the alloy also has certain strength.