Self-assembled 1–3-type Fe:LaSrFeO4 epitaxial nanocomposite film has been prepared using pulsed laser deposition by decomposing a ceramic La0.5Sr0.5FeO3 target in a high-vacuum system. Impacts of deposition temperature and energy density on the evolution of the microstructure and crystallinity of the Fe:LaSrFeO4 film have been investigated. It is found that Fe nanopillars are highly c-axis oriented at lower deposition temperature, and epitaxial at higher temperature, however, the epitaxial quality of the Fe:LaSrFeO4 film decreases if the deposition temperature is further increased. Besides the deposition temperature, the crystallinity of the Fe nanopillars can also be influenced by the energy density. Only at a specific temperature and an energy density, can high-quality 1–3-type Fe:LaSrFeO4 epitaxial nanocomposite film be yielded. Compared with the morphology image, the magnetic domains of Fe for the optimized sample can be clearly observed by magnetic force microscopy. Moreover, it is found that the saturation magnetization and coercivity of the sample under both field directions of parallel and perpendicular to nanowires are 1314 emu cm−3, 461 Oe and 1070 emu cm−3, 412 Oe, respectively.