This study was to explore the feasibility of immunofluorescence based on fluorescent nanoparticles (FNP) in the detection of acute myocardial infarction (AMI) marker Cardiac troponin I (cTnI), and analyze the clinical value of optimized rescue measures in the emergency treatment of AMI. FNPs were prepared with the soap-free emulsion polymerization with potassium peroxodisulfate (KPS), styrene (St), and acrylic acid (AA) as raw materials and Nile red (NR) as fluorescent dye. FNPs were then applied to lateral flow immunoassay (LFIA). The size and Zeta potential of the FNP were measured with transmission electron microscope (TEM) and laser granulometer (LGM), respectively. The fluorescence intensity and ultraviolet (UV)-visible absorption spectrum (AP) of the FNP were detected with the fluorescence spectrophotometer (FSM) and ultraviolet spectrophotome-ter (USM), respectively. The changes in functional groups in the test sample were determined with a Fourier transform infrared spectrometer (FTIR). The sensitivity (Sen) and precision (Pre) of cTnI content detection were analyzed comprehensively. 76 AMI patients were recruited as the research objects and rolled into a control group (conventional treatment, group C) and an observation group (optimized rescue measures, group O)) with 38 cases in each group. The cTnI levels of the two groups of patients were detected before and after the treatment. In addition, the cure rates, death rates, and complications of the two groups were counted statistically. It was found that when the KPS and AA were 0.1 g and 0.4 g, the particle size was about 300 nm, the maximum wavelength of the UV-visible AP of FNP was 552 nm, and the maximum fluorescence emission wavelength was 606 nm. After the FNPs were dyed, –CH characteristic peaks were found at 1,060 cm−1 and 2,926 cm−1 in nitrogen heterocycles and aromatic heterocycles, which were similar to NR. The upper limit of cTnI concentration was 80 ng/mL, and the coefficient of variation (CV) was 1.32%–1.86%. The cTnI value of patients in group O after treatment was obviously lower than that in group C (P < 0.05). The incidence of complications and death rate in the group O were considerably different from those in group C (P < 0.01). To sum up, FNP was adopted in the detection of AMI marker cTnI, and the LFIA based on FNP showed high detection Sen and Pre, which can be promoted in clinical detection. In short, the optimized rescue measures improved the survival rate of AMI patients effectively.