An interactive projection system and an interactive projection method are provided. The interactive projection method includes: generating a virtual image by using a projector; detecting an object on the virtual image by using a depth camera, wherein the object corresponds to a virtual scene; detecting a drawing operation corresponding to the virtual image by using the depth camera; and projecting the virtual scene on the virtual image in response to the object being placed on the virtual image, and generating a block on the virtual image according to the drawing operation.