The invention provides a composite foam membrane water purification system, which comprises: a filtering core group, wherein the filtering core group comprises a fore-lying filtering core and a reverse osmosis filtering core, and the filtering core group is provided with a raw water inlet and a purified water outlet communicated with the fore-lying filtering core, and is also provided with a purified water inlet, a wastewater outlet and a purified water outlet communicated with the reverse osmosis filtering core; and a foam membrane filtering part, wherein the foam membrane filtering part comprises a filtering bottle, a first water inlet, a first water outlet and a stored water inlet and outlet are formed in the filtering bottle, a soft water tank body is arranged in the filtering bottle,a rear-lying filtering core is arranged in the soft water tank body, the water inlet end of the rear-lying filtering core is communicated with the first water inlet, the water outlet end of the rear-lying filtering core is communicated with the first water outlet, and a water storage space communicated with the stored water inlet and outlet is formed between the outer side of the water tank body and the inner side of the filtering bottle. According to the invention, by arranging and applying the water purification system, the TDS value of the first cup of water obtained by restarting after thewater purification system is standby can be reduced.