In this study, amine functionalized opoka (OP@APTMS) via grafting with 3-aminopropyltrimethoxysilane (APTMS) were obtained through a mild process. The surfaces of the prepared OP@APTMS are functionalized with abundant amine groups. The OP@APTMS have been proven to be effective adsorbents for fast removal of gaseous HCHO, and its adsorption rate is three times more than that of commercial activated carbon (AC). On the other hand, the desorption rate of [email protected] is extremely lower than that of AC, exhibiting its potential applications as an efficient and safe adsorbent for highly efficient removal of indoor gaseous HCHO.