A sandglass type ocean engineering floating structure is provided with an upper structural body shaped as a circular truncated cone or frustum and a lower structural body shaped as a regular circular truncated cone or regular frustum; under a combined state, the smaller bottom surface of the upper structural body is fixedly connected with the smaller bottom surface of the lower structural body to form a junction surface; the axis of the upper structural body and the axis of the lower structural body are positioned on the same straight line; the larger bottom of the upper structural body acts as an upper deck of the floating structure and the larger bottom of the lower structural body acts as a lower plate underwater of the floating structure; the junction surface is a full-load waterplane of the floating structure.