Numerous wastewater flocculated sludge (WFS) is a global problem due to the considerable global environmental and public health burden, but sustainable and effective strategies for the resource utilization of WFS are still insufficient. Here, a facile and sustainable strategy was developed to regulate the surface structure of WFS for the fabrication of superhydrophobic ceramic coating. The structural transformation from the amorphous structure of WFS to hierarchical porous micro/nanocomposite structures was realized. Moreover, the designed ceramic coating maintained excellent superhydrophobic and self-cleaning properties over the entire pH range (1−14) or when applied to four different substrates. This work not only provides a new procedure for effective management of WFS and facile fabrication of superhydrophobic ceramic coating with excellent acid- and alkali-resistance and substrate-independent property, but also has potential applications in separation, catalysis and construction.