The invention relates to a diking method through filling sludge and a curing agent into mold bags. The method includes the following steps: step one, laying a layer of permeable filling mold bags provided with filling openings on a target mud flat surface; step two, pumping curing agent grout and sludge simultaneously into the filling mold bags from the filling openings through a curing agent pipeline and a slurry pipeline until the mold bags are full; step three, leaving the filling mold bags to stand until the sludge in the bags is solidified; step four, laying a next layer of filling mold bags on the layer, and repeating the step two and the step three; and step five, laying each following layer of mold bags sequentially according to step four and enabling the sludge in the bags to be solidified until a designed height is reached. According to the method, a technical scheme of separate slurry production and mixing filling is adopted, processes of mixing and stirring the sludge and the curing agent in advance are omitted skillfully, the curing agent grout can be prepared at an emptying point directly, materials and stirring equipment are not needed to be delivered to a construction site, and construction efficiency improvement and cost reduction are facilitated.