Receptor tyrosine kinases (RTKs) play a pivotal role in cell signaling through their activation via dimerization. Recent studies have demonstrated the importance of the temporal dynamics of RTK activity and downstream signals, such as ERK, in determining the cell fate. To better understand these dynamics, it is essential to develop methods capable of controlling the RTK activity with high temporal resolution. However, techniques for precisely modulating the activity of endogenous RTKs without requiring genetic modification remain insufficiently established. In this study, we developed a DNA aptamer agonist, Met-azo-aptamer, which enables reversible optical control of the activity of the c-Met receptor, a member of the RTK family. This was achieved by incorporating azobenzene, a photoisomerizable molecule, into a DNA aptamer that binds to c-Met. This design allows light-induced switching between the active and inactive structures of the aptamer. When the aptamer was applied to HeLa cells and exposed to ultraviolet or blue light, phosphorylation signals within the cells were activated in response to the light patterns. Furthermore, by variation of the light patterns, the Met-azo-aptamer successfully controlled the timing, amplitude, and duration of downstream ERK activation. The Met-azo-aptamer developed in this study offers a high-resolution method for investigating the relationship between RTK activation patterns and cell function or fate.