The invention relates to a water-based coating for a pipeline. The water-based coating for the pipeline comprises the following components: hydroxylated fiber resin, modified phenolic resin, asphalt, alkyd emulsion, carboxylic dibasic ester, isooctyl acrylate, man-made glass fiber, nano-powder, talcum powder, iron titanium powder, chromium oxide green, sodium hexametaphosphate, a methylalkylpolysiloxane solution, dodecyl mercaptan, a bactericide, a rust inhibitor, 1, 2-propylene glycol, additives and deionized water. The water-based coating for the pipeline has the following beneficial effects that the coating is good in adhesion, less prone to shedding and long in service life; furthermore, a preservative is added in the coating, so that the water-based coating can effectively prevent natural corrosion and microbial corrosion of the pipeline caused by iron bacteria.