Marble is one of the main materials used for ancient stone carvings and constructions. Many black crusts have appeared on the surface of marble relics during the period of industrial development. These not only reduce the artistic value seriously, but also lead to further deterioration through continuous absorption of various pollutants and more radiation heat. Therefore, cleaning measures are urgently needed. Based on the previous studies on marble carvings and black crusts in Beijing area, the ammonium carbonate method, ethylene diamine tetraacetic acid method and mechanical method were used to carry out cleaning trials for conparison. Furthermore, on-site tests were applied to six typical stone carvings at different places in Beijing to optimize the whole process. Instruments including a portable X-ray fluorescence spectrometer, a colorimeter and a microscope were used to evaluate the effects before and after cleaning. The contents of soluble salts in carvings were analyzed using ion chromatography. The results show that the ammonium carbonate method had the best cleaning effect on the black crusts on marble stone relics. A more efficient and reasonable cleaning scheme was thus obtained, which is helpful to the conservation of stone relics.