The invention belongs to the field studying the devices for soil and water conservation. The invention involves a topography-meter host based on integrative mainboards, which dynamically observe the landform in real-time and three-dimensions. The linear laser sources are accurately positioned with Ohm-shaped clamps, so as to emit parallel and equidistant laser-planes projecting onto a terrain in an experiment. The positions of the laser-sources on the mainboards are fixed with the Ohm-shaped clamps. The clamps do not only realize the convenient adjustment of the emission angle and spacing distance of the adjacent laser-sources, but also ensure a high accuracy of the positions and angles of the laser-sources even if the topography-meter host is moved. Several multi-segmented cases are freely spliced to observe the landforms with different heights in real-time. The invention is a novel topography-meter host which conveniently and accurately fixes the spacing distances and emission angles of the laser-sources, and the invention also satisfies the requirement in observing the landforms with different heights.