The work aims to study the parameters affecting morphology of laser etched patterns such as laser power and filling density, optimize working parameters for laser beam etching of 2 μm aluminum film/PI, and further improve etching quality. Finite element software ANSYS was adopted to simulate energy transfer and conversion process on Al film during laser etching of 2 μm aluminum film/in PI process, and reveal the relationship between etching morphology and laser process parameters of a single pulse. Based on the simulation results, Al film on polyimide substrate was etched with a LSP2000 laser etching system in the combinations of different laser power, scanning mode and filling density. Surface morphology of the laser etched sample was analyzed with scanning electron microscope (SEM). Neat etching edges of 2 μm Al/PI could be obtained under following parameters: a 1064 nm Nd: YAG laser with frequency of 20 kHz, pulse width of 100 ns, spot diameter of 40 μm, laser power of 5 W, radial scanning pitch of 0.04 mm, serpentine scanning mode, filling in direction of 45°, filling density of 0.03 mm, and scanning speed of 565.7 mm/s. Nanosecond etching process involves not only thermal interaction but also stress removal. Optimization of laser etching process parameter scan be used to obtain smooth etching edges and improve accuracy of laser etching.