Abstract: To improve the utilization of dust-depressor and reduce the dust concentration, we use forward osmosis experiment device to study wettability of inorganic compound solution. We obtain temperature penetration time plot according to the forward osmosis results of Na₂SO₄-SDS inorganic compound solution in 10 ℃, 15 ℃, 20 ℃, 25 ℃ 30 ℃, 35 ℃ and solution mass percent of 0%, 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%. The results show that the penetration time of Na₂SO₄-SDS distribution solution increases at first and then decreases with the temperature increasing; penetration efficiency is highest when solution mass percent is from 0.1% to 0.3% and temperature is from 20 ℃ to 25 ℃ range.