River and lake dredged sediment resource utilization method

The invention relates to a river and lake dredged sediment resource utilization method which comprises the following steps: S1, dehydration treatment: adding a prepared covalent bond type composite flocculant coated Fe3O4 into dredged sediment, uniformly stirring and mixing, coagulating, naturally settling, and removing overlying water to obtain flocculated and dehydrated sediment; s2, composting treatment: adding the prepared hydroxyapatite/tobermorite coated Fe3O4 composite material into the flocculated and dehydrated bottom mud, and carrying out aerobic composting to enable a composting product to meet the requirement of decomposition degree; and S3, post-treatment: airing the composted product, carrying out magnetic separation, and preparing the residual humic substance and other auxiliary materials into the seedling culture substrate. Compared with the traditional direct composting of the dredged sediment, the method overcomes the problems that the dewatering pretreatment difficulty of the dredged sedime