The invention discloses a sewage treatment filtercake by taking river sludge as a raw material and a manufacturing method, and the filtercake comprises the following components by mass percent: 80-100% of river sludge, 0-15% of flyash, 0-5% of red mud for steel production and 2-5% of swelling agent; the filtercake is obtained by adding 25-30% of water and 2-4% of pressing binder in terms of the mass of the raw material into the above components through the steps of mixing, pelleting, drying and high-temperature sintering successively. The filtercake in the invention has high main performance indexes such as film hanging property, water-gas distribution uniformity, bulk specific weight, strength, porosity, specific area and the like, and can be manufactured with a specified aperture and an apparent density conveniently by controlling the granularity and dosage of charcoal powder or mica powder, and has the advantages of wide sources of raw materials, simple production process, no pollution, low cost and high added value; the production equipment and technology in the current cement plants can be switched to producing ball-shaped filtercake of which the performance indexes for sewage treatment conform to the environmental protection requirements, thus achieving the effect of treating waste by waste.