The low cost and ease of deployment allows for integrated geophones to be deployed in very large numbers, often known as large arrays. This ability has facilitated many new directions in seismological research. Here, we offer a new application example, in which a dense array was used in imaging the details of the topography of the crustal–mantle seismic boundary. In 2015, an experiment with a large‐number and high‐density geophone array was conducted in the middle‐lower Yangtze River metallogenic belt (MLYRMB). During 10 days of continuous observation, there were five teleseismic events with high signal‐to‐noise ratio three‐component waveforms recorded by the array. Then, P‐wave receiver functions were calculated and adopted to image the Moho topography. The result shows that the Moho depth beneath the array varies significantly. The Moho topography beneath the MLYRMB region is deflected and characterized by mantle uplift that could be taken as a feature of intense crust–mantle interaction, such as mantle‐derived magma emplacement. The result indicates that receiver function research using dense geophone arrays can provide more detailed information about Moho topography as well as about multiscale crustal structures.