A defrosting system, comprising an auxiliary water path and a controller; wherein the auxiliary water path is arranged on a condenser side; and the controller comprises: a first unit, which is configured to obtain an ambient temperature; a second unit, which is configured to obtain a coil temperature of the auxiliary water path; and a third unit, which is configured to control the auxiliary water path to be connected to high-temperature hot water of a main water path according to the ambient temperature and the coil temperature of the auxiliary water path, wherein the third unit comprises: a first judging unit, which is configured to judge whether the ambient temperature meets a first condition; and a second judging unit, which is configured to judge whether the coil temperature of the auxiliary water path meets a second condition; wherein when the ambient temperature meets the first condition and the coil temperature of the auxiliary water path meets the second condition, the third unit controls the auxiliary water path to be connected to the high-temperature hot water of the main water path, characterized in that the first condition is: 5°C<Ta≤20°C, where Ta is the ambient temperature; the second condition is: Te≤5°C for a duration of t1, where Te is the coil temperature of the auxiliary water path, and t1 is 1 to 5 minutes. wherein the auxiliary water path is arranged on a condenser side; and the controller comprises: a first unit, which is configured to obtain an ambient temperature; a second unit, which is configured to obtain a coil temperature of the auxiliary water path; and a third unit, which is configured to control the auxiliary water path to be connected to high-temperature hot water of a main water path according to the ambient temperature and the coil temperature of the auxiliary water path, wherein the third unit comprises: a first judging unit, which is configured to judge whether the ambient temperature meets a first condition; and a second judging unit, which is configured to judge whether the coil temperature of the auxiliary water path meets a second condition; wherein when the ambient temperature meets the first condition and the coil temperature of the auxiliary water path meets the second condition, the third unit controls the auxiliary water path to be connected to the high-temperature hot water of the main water path, characterized in that a first unit, which is configured to obtain an ambient temperature; a second unit, which is configured to obtain a coil temperature of the auxiliary water path; and a third unit, which is configured to control the auxiliary water path to be connected to high-temperature hot water of a main water path according to the ambient temperature and the coil temperature of the auxiliary water path, wherein the third unit comprises: a first judging unit, which is configured to judge whether the ambient temperature meets a first condition; and a second judging unit, which is configured to judge whether the coil temperature of the auxiliary water path meets a second condition; wherein when the ambient temperature meets the first condition and the coil temperature of the auxiliary water path meets the second condition, the third unit controls the auxiliary water path to be connected to the high-temperature hot water of the main water path, characterized in that a first judging unit, which is configured to judge whether the ambient temperature meets a first condition; and a second judging unit, which is configured to judge whether the coil temperature of the auxiliary water path meets a second condition; wherein when the ambient temperature meets the first condition and the coil temperature of the auxiliary water path meets the second condition, the third unit controls the auxiliary water path to be connected to the high-temperature hot water of the main water path, characterized in that the first condition is: 5°C<Ta≤20°C, where Ta is the ambient temperature; the second condition is: Te≤5°C for a duration of t1, where Te is the coil temperature of the auxiliary water path, and t1 is 1 to 5 minutes.