The high strength ceramsite was prepared by using tin tailings (T), lake sediment (L) and fly ash floating beads (F) as raw materials and sodium silicate as binder. The effects of heat treatment system and sodium silicate content on the properties of ceramsite were investigated by orthogonal experiment and single factor optimization experiment. Based on the obtained results, under the condition that the raw material ratio of T, L, F is 65:25:10(ω%), the sodium silicate content is 32.5 mL / 100 g raw materials, the preheating temperature is 600 °C, and sintering at 1120 ℃ for 15 min, the obtained high-strength ceramsite with a density grade of 600 shows the following performance parameters: the 1-h water absorption is 0.41%, the cylinder compressive strength is 8.53 MPa. XRD results reveal that with the increase of sintering temperature, the phase transformation of Fe2O3→Fe3O4→MgFe2O4 exists in the ceramsite. The addition of sodium silicate provides part of the Si-O bond to form crystal phases such as sanidine, nepheline, which improves the strength of the ceramsite.