The invention relates to a pipeline cleaning process design which is mainly used for cleaning a medium pipeline of continuous casting equipment in the steel production process. The pipeline cleaning process mainly comprises the procedures of pipeline disassembly, assembly and connection, flushing, leakage testing, degreasing, primary acid pickling, secondary acid pickling, passivation, drying, waste liquid recovery, pipeline reinstallation and the like. According to the process, acid pickling and passivation processes of the medium pipeline are combined, degreasing and dual cleaning are carried out in the acid pickling process, and problems that the medium pipeline in continuous casting equipment is difficult to clean, low in cleaning quality, uneven in cleaning and the like due to many kinds of media, complex media and the like are solved. The cleaning efficiency of an existing process is improved, the cleaning cost is saved to a certain extent, waste liquid is uniformly recycled after cleaning, and the burden of chemical pollution products on environmental protection is relieved.