A safety control method for a gas water heater, comprising: obtaining a set value for output power of an exhaust fan in the gas water heater; obtaining an actual value of a rotational speed of the exhaust fan and a reference value of the rotational speed according to the set value for the output power, and calculating a difference between the actual value of the rotational speed and the reference value of the rotational speed; detecting the rotational speed of the exhaust fan; and correcting the rotational speed according to the difference, determining a wind pressure situation at an air outlet of the exhaust fan according to the corrected rotational speed and the set value for the output power, and adjusting the set value for the output power according to the wind pressure situation, wherein correcting the rotational speed according to the difference comprises controlling the corrected rotational speed to be equal to a sum of the rotational speed of the exhaust fan and the difference; the safety control method being characterised in that determining a wind pressure situation at an air outlet of the exhaust fan according to the corrected rotational speed and the set value for the output power and adjusting the set value for the output power according to the wind pressure situation comprises: controlling the set value for the output power to be reduced by a first predetermined value when it is determined that the wind pressure situation is a low wind pressure situation; controlling the set value for the output power to keep unchanged when it is determined that the wind pressure situation is a medium wind pressure situation; and controlling the set value for the output power to be increased by a second predetermined value when it is determined that the wind pressure situation is a high wind pressure situation. obtaining a set value for output power of an exhaust fan in the gas water heater; obtaining an actual value of a rotational speed of the exhaust fan and a reference value of the rotational speed according to the set value for the output power, and calculating a difference between the actual value of the rotational speed and the reference value of the rotational speed; detecting the rotational speed of the exhaust fan; and correcting the rotational speed according to the difference, determining a wind pressure situation at an air outlet of the exhaust fan according to the corrected rotational speed and the set value for the output power, and adjusting the set value for the output power according to the wind pressure situation, wherein correcting the rotational speed according to the difference comprises controlling the corrected rotational speed to be equal to a sum of the rotational speed of the exhaust fan and the difference; the safety control method being characterised in that determining a wind pressure situation at an air outlet of the exhaust fan according to the corrected rotational speed and the set value for the output power and adjusting the set value for the output power according to the wind pressure situation comprises: controlling the set value for the output power to be reduced by a first predetermined value when it is determined that the wind pressure situation is a low wind pressure situation; controlling the set value for the output power to keep unchanged when it is determined that the wind pressure situation is a medium wind pressure situation; and controlling the set value for the output power to be increased by a second predetermined value when it is determined that the wind pressure situation is a high wind pressure situation. controlling the set value for the output power to be reduced by a first predetermined value when it is determined that the wind pressure situation is a low wind pressure situation; controlling the set value for the output power to keep unchanged when it is determined that the wind pressure situation is a medium wind pressure situation; and controlling the set value for the output power to be increased by a second predetermined value when it is determined that the wind pressure situation is a high wind pressure situation.