First aid is to give immediate first aid to patients who have suffered accidental injuries or sudden diseases before the emergency medical personnel arrive at the scene or are sent to the hospital for treatment; myocardial infarction is a severe and emergency of coronary heart disease. It is often because of coronary atherosclerosis, plaque rupture, bleeding, or thrombosis, which leads to the acute and complete occlusion of the coronary arteries and acute necrosis of the myocardium. This article aims to investigate the effectiveness of a stratified emergency care team assisted by multidisciplinary first aid knowledge in acute myocardial infarction first aid, hoping to reduce the probability of acute myocardial infarction through first aid and nursing care. Business process reengineering is a management idea that reached its heyday in the 1990s and is usually defined as achieving workflow and productivity through the reorganization and optimization of corporate strategies, value-added operational processes, and the systems, policies, organizations, and structures that support them. This article first outlines the concepts and steps of medical image registration, analyzes the characteristics of current medical image registration methods, and uses the two most commonly used medical registration methods today; in this study, the BPR theory was used to construct the AMI emergency care process in the hospital, which effectively reduced the emergency delay time of AMI patients, improved the patient's emergency response, and increased the efficiency of emergency nurses' rescue work. The experimental results in this paper show that the sensitivities of the first four groups of ST↑III > II, ST ↓ aVL > I, STV3 ↓ /STIII↑≤1.2, STI ↓ ≥0.05 mV are 82.1%, 80%, 75.3%, and 60.3%, respectively. Their sensitivities are relatively close, both are greater than 50%; among them, ST↑III > II has the highest sensitivity, which is 80%. In terms of specificity, ST↑III > II, ST ↓ aVL > I, STV3 ↓ /STIII↑≤1.2, and STI ↓ ≥0.05 mV were 82.1%, 89.2%, 82.7%, and 65.2%, respectively. ST ↓ ≥0.05 mV has the lowest specificity, and ST ↓ aVL > I has the highest specificity.