The invention discloses a control method of the anti-freezing function of a new air ventilating system. Whether the system needs to get into or retreat from an anti-freezing pattern or not can be judged according to conditions, after the system gets into the anti-freezing pattern, the new air quantity can be gradually reduced and the return air quantity can be gradually increased, judgment is carried out once within a certain time, the system retreats from the anti-freezing pattern at any time when the conditions are proper, and the control method is more intelligent.