A liquid supply method for an atomizer and a liquid supply apparatus thereof, relating to the technical field of smoking simulation. The method includes : when a heating member generates heating, acquiring a resistance value of the heating member, (S110); obtaining a liquid supply rule according to the resistance value of the heating member, the liquid supply rule comprising at least one of a liquid supply speed for of using a pump to supply liquid to the atomizing chamber, and a liquid supply duration of using the pump to supply liquid to the atomizing chamber in a unit time period (S120); and controlling the pump to supply liquid to the atomizing chamber according to the liquid supply rule (S130). A problem of dry burning of an electronic cigarette can be solved, and effects of avoiding dry burning and liquid explodes and improving a smoking taste of electronic cigarettes are achieved.