In order to overcome the shortage of absorbability loss for HCHO-saturated sepiolite,static adsorption experiments were applied to evaluate the effects of heating temperature on absorbing traces of gaseous HCHO for sepiolite,and scanning electronic microscopy,X-ray diffraction,infrared absorption spectroscopy,thermogravimetry and BET specific surface area analysis were adopted to investigated the related mechanisms.It was resulted that silica-gel desiccant elevated the ability for sepiolite to absorb traces of gaseous HCHO and reduced the HCHO concentration lower than the legal safety upper limit.The sepiolite heated at temperature ≤ 400℃ held favorable HCHO absorption properties,while those heated at temperature ≥ 500℃ showed significantly reduced HCHO absorption properties.Under comprehensive characteristics,it is proposed that the crystalliferous water in sepiolite could chemically absorb HCHO and the structural microholes,basically composed of zeolite holes,could be occupied by HCHO through physical absorption.After heated at temperature ≥ 450℃,sepiolite lose the crystalliferous water irreversibly and the zeolite holes collapse that make the absorbability reduce drastically.The research supports sepiolite to regenerate absorbability by heating at temperature below 450℃ at which the escaped HCHO could be eliminated by burning,so sepiolite could enduringly remove traces of HCHO in the air by intermittently thermal regeneration.