This study investigates angiotensin II (Ang II)’s regulatory mechanism on renal outer medullary potassium channel (ROMK) activity in the distal convoluted tubule (DCT) during low potassium intake, focusing on the janus kinase 2 (JAK2) pathway activation mediated by the Ang II type 1 receptor (AT1R). Methods: Utilizing a low potassium diet mouse model, various methods including patch clamping, reverse transcription-quantitative polymerase chain reaction, Western blotting, and immunohistochemical staining were applied to analyze ROMK channel activity and the expression of related proteins. Results: The findings reveal that Ang II inhibits ROMK activity in the DCT2 membrane through AT1R activation, with the JAK2 pathway playing a central role. Further, inhibiting JAK2 reverses this effect, indicating its potential in hypertension treatment. Conclusion: This study provides novel insights into the role of Ang II in renal potassium excretion and hypertension pathophysiology.