A capacitive touch device and a sensing method thereof are disclosed. The capacitive touch device includes a touch panel, at least one touch detection unit and a processing unit. The touch detection unit scans the touch panel, obtains an N-bit sensed data and compresses the N-bit sensed data to an L-bit sensed data. The processing unit receives the L-bit sensed data, decompresses the L-bit sensed data to the N-bit sensed data and calculates a coordinate of a touch according to the N-bit sensed data. The present invention is capable of decreasing the time for transmitting the sensed data, the power consumption and the requirements for the memory capacity of the touch detection unit and the memory capacity of the processing unit.