This paper studied the feasibility of using green organic base to replace traditional inorganic base in sapphire UV-CMP. The effects of pH regulators on chemical and mechanical functions were researched by XPS, SEM, zeta potential and particle size analyses. The polishing effect of green organic base aminopropanol (AMP) is the best when the pH of the polishing solution is 11, compared with sodium metasilicate (SMSN) and KOH. Thus AMP can replace KOH in sapphire UV-CMP as a green alkaline pH regulator. However, with the increasing slurry pH values adjusted by the three alkaline reagents, the sample removal rate decreases significantly. And the reduction of organic base is greater. The main causes for the decreasing sapphire removal rate are the particle aggregation and the rising electric potential energy between abrasive particles, which leads to the increase of the distance between particles. This severely reduces the number of abrasives included in mechanical removal. The mechanical action is weakened, resulting in a serious decrease in the removal rate.