The invention provides a displaying method for complex three-dimensional terrain. The method comprises the steps that, firstly, data conversion is conducted, and conversion and processing are conducted on read-in three-dimensional terrain data; secondly, data processing is conducted, after data conversion is finished, an OpenGL software interface is adopted to carry out processing on the converted three-dimensional terrain data, and the three-dimensional terrain data are converted into the data which a computer can identify and process; thirdly, texture manufacturing is conducted, the data range is divided into a plurality of sub ranges, and the data in each sub range correspond to the same terrain color; fourthly, three-dimensional terrain display is conducted, and parameter setting, terrain model mapping, viewpoint-model transformation, projection transformation and viewport transformation are conducted on the three-dimensional terrain model. The displaying method for the complex three-dimensional terrain has the advantages of Supporting the displaying of the terrain with the large range and the complex earth surface situation, ensuring the good display effect, and supporting mouse and keyboard operations to achieve wandering of the three-dimensional terrain.