Protein dimerization or oligomerization is a key factor in signal transduction processes. It is of great significance to develop novel strategies for investigating protein dimerization in cells and in vivo. Herein, we report a nongenetic proximity-induced fluorescence resonance energy transfer (FRET) strategy based on DNA tetrahedron for visualizing the receptor dimerization. In this nanostrategy, the aptamer serves as the recognition sequence for specifically binding to the receptor monomer. As long as the receptor dimers exist, the proximity switch probes hybridize with each other to induce the FRET between Cy3 and Cy5. Good stability of the DNA tetrahedron in this approach ensures the application value in multiple biological samples. This work provides a new way for developing novel protein dimerization visualization nanostrategies.