In　this　study,　an　aptamer　biosensor　based　on　weak　value　amplification　is　proposed　for　the　first　time.　The　feasibility,　selectivity,　robustness,　and　high　detection　accuracy　of　aptamer　sensors　are　verified　by　the　adenosine　triphosphate　(ATP)　detection　experiment.　The　weak　measurement　system　shows　high　sensitivity　to　phase　changes,　corresponding　to　refractive　index　changes,　attributed　to　the　changes　in　the　spatial　configuration　of　the　aptamer　nucleic　acid　chain　after　specifically　capturing　the　target　molecule.　As　the　main　energy　source　in　the　body,　ATP　plays　an　important　role　in　many　biological　processes,　and　its　detection　is　of　great　significance　to　study　cell　metabolism,　biochemical　pathways,　and　early-stage　disease　diagnosis.　This　work　provides　a　new　labelingfree　detection　scheme　for　aptamer　sensors　and　offers　a　high-precision　and　specific　detection　of　small　biological　molecules　based　on　weak　measurement　biosensors.　The　proposed　method　is　of　great　significance　to　the　development　of　aptamer　sensors　and　weak　value　amplification　technology.