A touch point sensing method and an optical touch system are provided. The optical touch system includes a first lens and a second lens. The touch point sensing method includes the following steps. Images including at least two touch objects in a touch detecting area captured by the first lens and the second lens are obtained and analyzed. Based on the obtained images, distance values between the first touch signal group at the first instant and the first and second touch signal groups at the second instant are calculated for determining whether the first and second touch signal groups at the second instant are overlapped. When the first and the second touch signal groups at the second instant are overlapped, locations of the touch signals in the first touch signal groups and in the second touch signal groups are exchanged.