In order to relieve the contamination of drilling mud in ultra-low permeability reservoir of carbonate rock，the corrosion effect of compound acid components on mud cake and core was evaluated by response surface regression analysis of the difference between dissolution rate of mud cake and core. The appropriate formula of plugging removal agent was determined. The plugging effect of compound acid on core was investigated and the plugging mechanism was analyzed. The results showed that four components were arranged according to their influence on dissolution efficiency of mud cake in following order: H₂O₂>HCl>HF>HAc，and that on dissolution efficiency of carbonate rock in following order: HCl>HAc>HF>H₂O₂. When the formula of plugging agent was 9.2% HCl+1.3% HF+5% H₂O₂+15% HAc，the recovery rate of core permeability after plugging removal was up to 130%.The compound acid had retarding property，and the damage of core could be reduced to minimum when the plug was removed. The stratum structure could be effectively protected so as to achieve the purpose of deep acidification.