Solid waste materials such as dewatered sludge from urban sewage treatment plants, waste mud from ceramic factories, fly ash, slag from biomass gasification furnaces, and rice husks were selected as raw materials to prepare water-absorbing ceramsite for sponge cities. Research indicates that when the sintering temperatures are 950 ℃, 1000 ℃ and 1050 ℃ respectively, with holding times of 0 h and 1 h, the primary crystal phases of the ceramsite include SiO2, Na(AlSi2O6), (Ca, Na)(Si, Al)4O8, CaSiO3, Al2SiO5 and NaFeO2. As the sintering temperature and holding time increase, the porosity of the ceramsite decreases significantly from 54.88% to 17.18%, the bulk density increases from 380 kg/m3 to 660 kg/m3, and the water absorption rate drops from 59.97% to 11.69%. However, the single particle compressive strength and water storage capacity of the ceramsite do not exhibit a consistent trend. The single particle compressive strength ranges from 0.62 MPa to 11.24 MPa, while the water storage capacity varies between 37.22% and 47.90%. Furthermore, leaching tests for heavy metals and pH in the ceramsite confirm compliance with water quality standards required for sponge city construction. The overall performance of the produced ceramsite satisfies the demands of sponge city construction and provides a viable reference for utilizing solid waste in the production of water-absorbing ceramsite for such applications.