The dehumidified adsorption system of expanded perlite in a closed space was designed and orthogonal experiments of three-factor and three-level and single factor for current velocity of wet air, sorbent layer, laid density of sorbent were processed. The effect of the above diversified factor on dehumidification performances was analyzed. The experimental results show that dehumidified velocity increases with air current, and dehumidified time decreases accordingly, higher current velocity of wet air is adopted within a certain scope, which increases dehumidification efficiency. And dehumidification ability improves with adsorbent layer increment. With laid density of adsorbent increment, the ability of heat and mass transfer between wet air and adsorbent grain has improved. Dehumidification velocity increases, and consuming time decreases correspondingly.