Objective To investigate the effect of point-of-care test (POCT) on the rescue of hyperkalemia patients in emergency departments. Methods A total of 86 patients with hyperkalemia who underwent arterial blood gas analysis from January 2020 to November 2021 were selected as study subjects. The on-site diagnosis and treatment effects of these subjects were analyzed, and the advantages of POCT in the diagnosis and treatment of hyperkalemia were summarized. Results Among the 86 emergency hyperkalemia patients, 43 cases underwent routine blood gas analysis and 43 cases underwent POCT for arterial blood gas analysis. POCT effectively shortened the waiting time for test reports, provided a basis for rapid diagnosis and treatment of patients' conditions, improved early diagnosis rate, opened easy access, prevented the occurrence of complications of hyperkalemia, reduced mortality, and improved the survival rate and quality of life of patients (P<0.05). Conclusion POCT can shorten the time to obtain reports, provide evidence for diagnosis and treatment, give timely treatment and interventions, improve early diagnosis rate, and elevate patients' satisfaction.