The invention discloses a forward osmosis-membrane distillation integrated water treatment device and application thereof, and belongs to the technical field of micro-pollution water source water treatment. The device comprises a raw water tank, a forward osmosis unit, a water sucking tank, a circulation tank, a heater, a membrane distillation unit and a cooling tank, wherein the forward osmosis unit comprises a low osmosis pressure unit, a forward osmosis membrane and a high osmosis pressure unit; the water sucking tank comprises an electric conductor; the circulation tank comprises the heater, a liquid level controller and a temperature controller; the membrane distillation unit comprises a hot material chamber, a lyophobic micro-pore membrane and the cooling chamber; the raw water tank is in circulation connection with the low osmosis pressure unit; the water sucking tank is in circulation connection with the high osmosis pressure unit; the circulation tank is in circulation connection with the water sucking tank; the hot material chamber is in circulation connection with the circulation tank; the cooling chamber is in circulation connection with the cooling tank. Due to adoption of the forward osmosis unit and the membrane distillation unit, the device is convenient to mount and simple to operate, has a very good removal effect on pollutants in water and has good application prospects in practical life.