Traditional adsorbents are normally suffered from a low adsorption capacity that has a finite saturated adsorption capacity. We reported herein a hierarchical self-growing porous calcium silicate hydrate (CSH) that uses biowaste as the precursor and is highly efficient in wastewater purification. In the process of phosphorus removal, CSH can react with phosphorus in water and grow into the hydroxyapatite (HAP). The generation of HAP further increases the active sites while maintains the porous structure of pristine CSH. Subsequently, the HAP could conduct the efficient extraction of Pb²⁺ from wastewater based on the ion exchange between Ca²⁺ and Pb²⁺. Clearly, the CSH structure has self-growing structure using the pollutants as the building blocks, not only achieving high adsorption capacity for pollutants, but also maintaining the hierarchically porous structure that supports the high efficiency in the next cycling. We provide here an intriguing pathway to tackle bottleneck of the traditional adsorbents, i.e., a finite saturated adsorption capacity.