The invention provides a dynamic adjusting method and system for temperature of a continuous hot-dipped aluminum-zinc steel strip and melt. The temperature dynamic adjusting method comprises the steps: once the height of a condensation line on the current steel strip is detected to be in a first pre-set range/a second pre-set range, correspondingly controlling a plating pot heater to increase/lower the heating temperature for the aluminum-zinc melt; and acquiring the current temperature of the aluminum-zinc melt, performing the addition operation for the acquired temperature and a pre-set standard temperature difference to obtain a target temperature of the steel strip, and adjusting the current temperature of the steel strip according to the target temperature by virtue of a steel strip cooling system. By referring to the condensation line and the aluminum-zinc melt, the control on the continuous hot-dipped galvanizing temperature of the steel strip is realized, and the stability and the accuracy are relatively high.