In this study, the protective effects of the Ganoderma atrum polysaccharide (PSG-1) on selected tissue (liver, spleen, kidneys and intestine) toxicity induced by acrylamide (AA) in SD rats were investigated. The results showed that pretreatment with PSG-1 could prevent AA-induced damage to liver and kidney functions by increasing the activities of ALT, AST and ALP and the levels of TG, BUN and CR in the serum of AA-treated rats. PSG-1 could also maintain the intestinal barrier function and permeability by preventing the reduction of the serum D-Lac and ET-1 levels in the intestine of AA-treated rats. In addition, AA-induced DNA damage, as indicated by an increase of the 8-OHdG level, was alleviated by pretreatment with PSG-1. Histological observations of the tissues confirmed the protective effects of different doses of PSG-1. Moreover, PSG-1 supplementation reduced oxidative stress and inflammation in rats by upregulating the superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities and IL-10 levels, and preventing the overproduction of malondialdehyde (MDA), IL-1β, IL-6, and TNF-α. Thus, these findings suggest that PSG-1 effectively prevents AA-induced damage in the liver, spleen, kidneys, and intestine of rats, partially by alleviating the inflammatory response and oxidative stress and protecting the intestinal integrity and barrier function.