A kind of cleaning technology for ICE cylinder block is introduced:before other parts and components or accessories are mounted onto a cylinder block, using process cleaning room to clean the cylinder block, after assembly, using reciprocating double cleaning room. It could solve the disadvantages of traditional cleaning method, which can not satisfy the cleaning requirements of varied cylinder block, and thus guarantees the cleaning effect. Application results show that this technology features high adaptability, easy operation, safe and reliable performance and good cleaning effect and could ensure the cleaning quality of different in-line and V configuration cylinder blocks, and could achieve good technical and economic benefits.