Scan method of touch signal

The invention provides a scan method of a touch signal. Different scanning impulse signals, which are corresponding to a plurality of drive lines in quantity, are used to scan simultaneously, and each scanning impulse signal is encoded correspondingly. Meanwhile, all scanning impulse signals are synchronously received by each reception line in a plurality of reception lines, and a control chip is used to decode received signals received by each reception line so as to determine the sources of different signal fields in the received signals. When a finger touches, according to the code of a signal field with the reduced semaphore, it is determined that the drive line touched by the finger is the drive line providing the scanning impulse signal corresponding to the code,, and the position of the touch is located by combining with the reception line corresponding to the received signal of the signal field with the reduced semaphore. The scan method of the invention enables an In Cell type touch display device to reduce the time of scanning touch signals and increase the time of scanning display signals, thereby prompting the In Cell type touch display device to develop to have a higher resolution ratio.