The invention discloses a sterilizing cushion for a host and a preparation method thereof. The preparation method comprises the following steps of: (1) adding abrotani herba, rhubarb root and rhizome,gentiana macrophylla, tripterygium wilfordii, rhizoma atractylodis, plantain seed, christina loosestrife, fructus evodiae and fructus aurantii immaturus in water for decoction, and performing filtration to obtain a filtrate so as to obtain a Chinese herbal medicinal extract; (2) performing soaking on attapulgite, cyclodextrin, glycerin fatty acid ester and the Chinese herbal medicinal extract, then performing filtration to obtain a filter cake, drying the filter cake, and then conducting ball milling to obtain ball milled powder; (3) performing activation treatment on the ball milled powder in the presence of UV light to produce a degerming agent; (4) mixing polyethylene plastic particles, dilauroyl peroxide, stearic acid, dioctyl phthalate, vaseline, sodium bicarbonate, calcium carbonateand the degerming agent, and conducting molding to obtain an expanded polyethylene foam material; and (5) filling a cushion cover with the expanded polyethylene foam material to obtain the sterilizing cushion for the host. The cushion prepared by using the preparation method has an excellent effect of sterilization.