An infrared sensor module, a touch sensing method thereof, and an auto calibration method applied to the same are disclosed, the touch sensing method includes turning on the infrared sensor module which includes a sensor block with a light receiving region and is arranged to be perpendicular to a surface of a display panel, the light receiving region being divided into m×n blocks (where, each of m and n is a natural number of two or more) arranged in m rows by n columns, each of the blocks having a plurality of light receiving pixels arranged in a row direction, scanning optical signals of each block, selecting the block having maximum output optical signals with respect to the blocks of each column, and summing the optical signals of the light receiving pixels of the block selected from the column.