A method for reminding a user about a water purifier includes receiving total dissolved solids (TDS) data reported by the water purifier, updating accumulative TDS data corresponding to the water purifier according to the received TDS data, calculating a cleaning period of the water purifier according to the accumulative TDS data and a preset maximum cleaning period, and sending a reminder message to a terminal associated with the water purifier to remind the user to clean the water purifier if the cleaning period satisfies a preset condition. The received TDS data is detected after the water purifier performs water purification and the accumulative TDS data reflects an accumulation of total TDS data of the water purifier since a latest cleaning.