Since the implementation of the ladder water price system for 10 years, the total domestic water consumption in China has not decreased but increased. So it is an inevitable requirement to improve and perfect the system to evaluate the effectiveness of the system. Based on the water consumption data of 2335 urban households in Fujian Province in 2021, the study empirically tested the impact of stepped water prices on household water consumption by using simultaneous equations to control endogenous. It is found that the ladder water price has a constraint effect on the water saving of households, and the household water saving behavior will increase by 4.107% for every 1% increase in the household water expenditure coefficient. However, due to the dynamic adjustment relationship between the coefficient of household water bill expenditure and the level of household water-saving behavior, it is difficult for the current ladder water price to reduce the total domestic water consumption, which shows that the household water consumption is stable. The constraint effect of step water price is only proportional to the difference between the first and second gradient water price, which indicates the effectiveness of the step water price system and the imperfection of the current water price standard. The stable exertion of the constraint effect of step water price requires timely adjustment of the step water price standard. When the water price adjustment period exceeds 57 months (4.75 years), the constraint effect of step water price is no longer significant.