Smart IC cards are used for smart IC card water meters, using modern microelectronics technology, modern sensing technology, and smart IC card technology to measure water consumption and transfer water data and settlement transactions. The IC card containing the amount of money is inserted into the IC card reader/writer in the water meter. After the amount is recognized and downloaded by the microcomputer module, the valve is opened and the user can use the water normally. In addition to recording and electronically displaying water consumption, it can also automatically control the water consumption according to the agreement, and automatically calculate the water fee for the stepped water price. At the same time, it can store water data. Data transfer and transaction settlement are performed through smart IC cards. Users can independently decide the time and amount of payment, which increases the user's autonomy.