A display device and a data driver thereof. The data driver comprises a first boost circuit for receiving a supply voltage value and generating at least one preset voltage value, a first grid clock generation circuit electrically coupled to the first boost circuit and used for receiving a plurality of sequence signals and the at least one preset voltage value and generating at least one first sequence signal, a first potential conversion circuit for receiving the at least one first sequence signal and generating at least one first grid sequence signal, and a data driving circuit for receiving the above sequence signals and generating a plurality of display data.