Di(2-ethylhexyl)　phthalate　(DEHP)　is　an　endocrine　disrupting　compound　that　is　often　used　as　a　plasticizer　and　tends　to　migrate　in　the　environment　and　accumulates　in　the　human　body　causing　harm　to　humans.　Thus,　a　simple,　label-free,　enzyme-free,　high　selective　and　ultrasensitive　electrochemical　aptasensor　has　been　constructed　for　detection　of　DEHP　based　on　the　self-assembly　of　DNA　nanostructure　signal　amplification　strategy　in　this　paper.　The　DNA-junction　nanostructure　is　made　of　hairpin　1　(HP1),　hairpin　2　(HP2),　hairpin　3　(HP3)　and　quarter　sequence　(QS).　Without　DEHP,　the　electrochemical　detection　response　is　very　low.　Only　when　the　aptamer　binds　to　the　target　and　detaches　from　the　electrode　surface,　the　DNA-junction　is　trapped　on　the　electrode　surface,　enhancing　the　electrochemical　signal.　This　is　because　the　DNA-junction　nanostructure　is　rich　in　guanine,　which　is　able　to　adsorb　more　methylene　blue　(MB)　for　the　purpose　of　enhancing　the　detection　signal.　The　linear　detection　range　of　the　obtained　aptasensor　is　0.1　ng　mL−1　to　5000　ng　mL−1　and　the　limit　detection　is　0.04　ng　mL−1.　Finally,　the　proposed　aptasensor　has　been　applied　to　analyze　DEHP　in　real　samples,　laying　the　foundation　for　its　utilization　in　environmental　water　samples　and　food　safety.　©　2022　Elsevier　B.V.