With the rapid development of ultra-short pulse laser technology，picosecond laser cleaning technology has gradually been applied in the field of cleaning and preservation of precious cultural relics. This article conducts experimental research on the cleaning of surface contaminants on stone cultural relics using picosecond laser with a wavelength of 1 064 nm. Firstly，homemade stone cultural relic samples are used，and changes in surface roughness of the samples after focusing laser and defocusing laser cleaning are measured by confocal microscope，comparing the effects of defocusing state on laser cleaning. Based on the cleaning experiments of stone cultural relic samples，exploration of optimization parameters for laser cleaning of stone cultural relics is conducted. Through experiments，the optimized parameters for picosecond laser cleaning of stone cultural relics with a wavelength of 1 064 nm are obtained as follows：power density of 2 J/cm²，spot diameter of 110 μm，scanning speed of 1 000 mm/s，scanning interval of 0.01 mm，and cleaning frequency of 7 times. The results suggest that the experimental results obtained from samples of stone artifacts are equally relevant to authentic artifacts. The experimental results presented in this paper bear significant importance in the exploration of optimization parameters for laser cleaning of stone artifacts.