A composite shoe sole, composed of an upper layer and a lower layer, wherein the upper layer is integrally formed of a soft material and the lower layer is integrally formed of a hard material, the lower layer being formed with a notch at a location corresponding to a right side of thenar, or right-side region of phalanx, the upper layer being formed with a projection at a location corresponding to the notch, such that the upper layer and lower layer are joined to each other by means of engagement between the projection and notch to form a shoe sole having a soft upper layer with elastic and shock-absorbing effects for relieving foot pressure, and a hard lower layer for providing upward support to the soft upper layer so as to prevent cave-in, thereby providing good bottom support, elastic air cushioning and shock-absorbing effects.