A touch display device, comprising: a touch display panel having multiple data lines and multiple gate lines arranged therein, having multiple touch electrodes arranged therein, and having multiple touch lines, which are electrically connected to the multiple touch electrodes so as to correspond to the multiple touch electrodes, arranged therein; a driving circuit; wherein the driving circuit comprises a touch driving circuit configured to drive at least one touch electrode among the multiple touch electrodes; and a touch controller (T-CTR) configured to sense whether there is a touch made by at least one of a finger and a pen, or a position of the touch on the basis of touch sensing data received from the touch driving circuit, wherein the touch controller (T-CTR) is grounded to a primary ground, the touch display panel is grounded to a secondary ground which is a ground different from the primary ground, and the touch display device further comprises a ground modulation circuit configured to apply a modulation signal (PWM, PWM') to the primary ground or the secondary ground such that one ground voltage among a primary ground voltage (Vgnd1) of the primary ground and a secondary ground voltage (Vgnd2) of the secondary ground becomes a modulated ground voltage as compared with the remaining ground voltage wherein the driving circuit is configured to simultaneously perform display driving and touch driving, wherein, with reference to the primary ground voltage (Vgnd1), the secondary ground voltage (Vgnd2) and a touch driving signal applied to the touch electrodes are modulated signals, and the secondary ground voltage (Vgnd2) has at least one signal characteristic corresponding to a signal characteristic of the touch driving signal among signal characteristics comprising a frequency, a phase, a voltage polarity, and an amplitude. a touch display panel having multiple data lines and multiple gate lines arranged therein, having multiple touch electrodes arranged therein, and having multiple touch lines, which are electrically connected to the multiple touch electrodes so as to correspond to the multiple touch electrodes, arranged therein; a driving circuit; wherein the driving circuit comprises a touch driving circuit configured to drive at least one touch electrode among the multiple touch electrodes; and a touch controller (T-CTR) configured to sense whether there is a touch made by at least one of a finger and a pen, or a position of the touch on the basis of touch sensing data received from the touch driving circuit, wherein the touch controller (T-CTR) is grounded to a primary ground, the touch display panel is grounded to a secondary ground which is a ground different from the primary ground, and the touch display device further comprises a ground modulation circuit configured to apply a modulation signal (PWM, PWM') to the primary ground or the secondary ground such that one ground voltage among a primary ground voltage (Vgnd1) of the primary ground and a secondary ground voltage (Vgnd2) of the secondary ground becomes a modulated ground voltage as compared with the remaining ground voltage wherein the driving circuit is configured to simultaneously perform display driving and touch driving, wherein, with reference to the primary ground voltage (Vgnd1), the secondary ground voltage (Vgnd2) and a touch driving signal applied to the touch electrodes are modulated signals, and the secondary ground voltage (Vgnd2) has at least one signal characteristic corresponding to a signal characteristic of the touch driving signal among signal characteristics comprising a frequency, a phase, a voltage polarity, and an amplitude.