Anti-freezing protection system for air conditioner as well as air conditioner

The invention provides an anti-freezing protection system for an air conditioner as well as the air conditioner. The system comprises a regulating valve opening degree controller which is used for judging whether an anti-freezing protection signal for presenting that the temperature of gas flowing out from a heat coil pipe is lower than a low-temperature threshold value is obtained or not; if the anti-freezing protection signal is obtained, opening degree of a regulating valve of the heat coil pipe is regulated to be biggest, otherwise, a set gas temperature of an air feeding section of the air conditioner and a gas temperature of a mixing section are obtained; a temperature difference value between the set temperature of the air feeding section and the gas temperature of the mixing section is obtained by calculating; an opening degree value which is matched with the temperature difference value is obtained according to a preset mapping table; opening degree of the regulating valve of the heat coil pipe is re