Water purifier and water preparation method thereof

A water production method of a water purifier, wherein, the water purifier comprises:

• a reverse osmosis membrane device comprising a raw water port, a purified water port and a waste water port;
• a water storage device which is provided therein with a first chamber of which a volume can be adjusted, the first chamber being communicated with the raw water port and the purified water port, respectively;
• when the water purifier is in a water production state, communicating the purified water port with the first chamber and disconnecting the raw water port from the first chamber such that purified water flowing out of the reverse osmosis membrane device flows into the first chamber;
• when the water purifier is in a cleaning state, communicating the raw water port with the first chamber such that the purified water in the first chamber flows into the raw water port of the reverse osmosis membrane device.

A water purifier, wherein, the water purifier comprises:

• a reverse osmosis membrane apparatus having a raw water port, a purified water port and a waste water port;
• a water storage apparatus which is provided therein with a first chamber having a volume regulatable;
• the first chamber can be communicated with the raw water port and the purified water port;
• the water storage apparatus has an isolator which partitions an interior of the water storage apparatus into the first chamber and a second chamber that are isolated from each other, and the second chamber can be communicated with a water source;
• the water source supplies raw water;
• and the isolator can regulate sizes of the first chamber and the second chamber.