The dynamic-load mechanical of laser solid forming (LSF) GH4l69 Ni-based superalloy is influenced by the coarse columnar grains formed in LSF processing and then its application in jet engines like turbine disks is limited. The previous study showed that the grain structure of the LSF GH4l69 superalloy can be refined by recrystallization processing during post heat treatment. In this work, the microstructure, interface and crystal orientation of the as-deposited and heat treated LSF GH4169 superalloy samples were investigated by EBSD analysis. It was found that the crystal orientations of grains become more randomly organized as the grain structure of the LSF GH4169 superalloy was refined by heat treatment and the holding time of heat treatment was increased. Subsequently, microstructural anisotropy existed in the as-deposited samples was disappeared in the heat treated samples and the fraction of high angle grain boundary was increased greatly. < 111> 60° twin crystal boundary was presented during the later period of recrystallization and the volume fraction of the twin crystal boundary reached up to 44%. This indicated that the formation of twin crystal boundary during static recrystallization of LSF GH4169 samples played an important role in the refinement of grain structure. Sub-grain and grain-boundary migration nucleation were the main nucleation mechanisms at the beginning of the recrystallization and nucleation related to twin was one of the most important mechanisms in the later period of the recrystallization.