The invention discloses a water heater and a control method thereof. The control method of the water heater comprises the following steps that the number of times of water using in each waste use timeperiod of every day in a previous cycle is counted, and when the total numbers of the times of water use in the water use time periods are larger than or equal to a preset time number, the time periods are regular time periods; the average water use quantities of all the regular time periods are counted, and when the average water use quantities are larger than or equal to a first preset water use quantity, the regular time periods corresponding to the average water using quantities are high-temperature time periods; and in the high-temperature time periods, the water temperature in the waterheater is increased to a first preset temperature. According to the technical scheme, water is heated to the first preset temperature only in the high-temperature time periods, and energy saving of the water heater is achieved in the time periods with little water use while it is ensured that the enough water can be used in water use peak periods.