The invention relates to a control device for the irradiation dose of an irradiation device, and provides a method for measuring the isotopic abundance ratio of uranium in particles through accelerator mass spectrometry. The method aims to solve the problems that an analysis method for the isotopic abundance ratio of uranium in existing environment sample particles is not high in analysis result accuracy, and interference is serious in the analysis process. The method comprises the following steps that 1, the sample particles are separated from a carrier and transferred to a graphite flake through ultrasonic oscillation; 2, the sample particles are transferred into a scanning electron microscope; 3, the uranium-bearing particles are found; 4, the uranium-bearing particles are dissolved; 5, a target is manufactured; 6, ruling is carried out; 7, accelerator parameters needed by each uranium isotope are determined; 8, the counting rate of each uranium isotope is measured; 9, the isotopic abundance ratio of the uranium is calculated. The problem that isotopic abundance ratio analysis of the uranium in the particles has polyatomic ion interference is solved, abundance sensitivity is obviously improved, the obtained analysis result is accurate, and the defect in an existing analysis method is overcome.