It is proved that the method of hydrolyzing cellulose in dilute sulfuric acid can hydrolyze cellulose at a certain temperature and under the condition of acidic catalyst, and finally produce glucose: glucose is a polyhydroxyaldehyde with aldehyde groups in its molecule, which has strong reducibility. Under alkaline conditions, the newly prepared copper hydroxide suspension can be reduced to brick-red Cu2O precipitate, and can also react with silver ammonia solution through silver mirror.