The invention discloses a gas water heater control method. The method specifically comprises the following steps of S1, starting a preheating function of a gas water heater in a standby state; S2, starting a water pump of the gas water heater; S3, detecting a water flow on a main water path of the gas water heater, entering the step S4 when the water flow is larger than a preset starting water flow, and otherwise, keeping the standby state of the gas water heater; S4, igniting the gas water heater to enter a preheating mode; S5, detecting a water return temperature of the gas water heater, completing preheating treatment and closing the water pump when the water return temperature is larger than a preset preheating temperature, and otherwise, controlling a working state of the gas water heater through the change of the heat exchange amount of the gas water heater; and S6, keeping burning of the gas water heater when the water flow on the main water path of the gas water heater is larger than a preset shutdown water flow, and otherwise, turning off and closing the gas water heater. The invention further discloses the gas water heater. According to the control method, in the preheating process, rapid pump closing can be realized through recognizing hot water starting action of a user, so that electric power consumption is reduced, and the product intelligentization is embodied.