A touch device and a method for detecting touch on the touch device are provided. The method includes the following steps. A plurality of touch values corresponding to a plurality touch region of a touch panel are obtained. A touch block is determined according the touch values and a touch threshold value, which the touch regions within the touch block are adjacent to one another. The touch values of the adjacent touch regions within the touch block are compared with one another to determine whether there is a touch value trough point in the touch block. It is determined that whether the touch block corresponds to a single touch or a multi-touch according to whether there is the touch value trough point in the touch block.