Spinel lithium ferrite LiFe5O8 (LFO) has attracted robust research interests due to their potential applications in isolators, circulators, and phase shifters. In this work, a series of LFO thin film with various thickness were fabricated on SrTiO3 (STO) single-crystalline substrates by pulsed laser deposition technology. We systematically investigated the influences of the thickness of LFO thin film on the crystal structure and magnetic properties. The in-plane lattice parameter a and in-plane lattice parameter c were modulated by controlling the thickness of LFO thin film, which was confirmed using reciprocal space mappings (RSMs) technology. Furthermore, the microwave magnetism of LFO thin film with various thickness were studied systematically by ferromagnetic resonance (FMR) measurement. Moreover, with increasing the thickness of LFO thin film from 50 to 180 nm, the difference of the ferromagnetic resonance field between easy- and hard-magnetization axis can be enhanced and reach to 330 Oe. These results illustrate that dynamic magnetic properties can be controlled by tuning the thickness of LFO thin film. Our work provides an effective method to tailor the lattice parameter and modify the magnetic properties of the LFO thin film and contributes to further design high-frequency functional device.