An optical touch apparatus is disclosed. The optical touch apparatus comprises a light source emitting module, an optical module, a light sensing module, and a processing module. The optical module and the light sensing module are set around a surface of the optical touch apparatus. The light source emitting module sequentially emits scanning lights uniformly distributed above a direct scanned region of the surface according to a time sequence. When an object forms a touch point on the surface, the object will block the scanning lights and reflected lights reflected by the optical module. The light sensing module generates a sensing result according to the condition the light sensing module receives the scanning lights and the reflected lights. The processing module determines the position of the touch point according to the time sequence and the sensing result.