<p>Abundant microborings are observed in the ooids of the Cambrian Miaolingian Series, Mantou Formation in the southern North China Block. The morphological characteristics, distribution patterns, and genetic mechanisms of these microborings were systematically investigated using petrographic observations, scanning electron microscopy, in situ laser Raman spectroscopy, and laser ablation-inductively coupled plasma–mass spectrometry. The microborings can be classified into three types: isolated vertical microborings, dense vertical microborings, and micritized microborings. The evolution from isolated microborings to dense vertical microborings and finally to micritized microborings reflects a gradual intensification of bioerosion by microboring organisms and their microcrystalline destruction of oolitic laminar structures. These microborings, likely formed by microorganisms similar to modern cyanobacteria, exhibit comparable features to those by contemporary cyanobacteria. In situ analysis of trace and rare earth elements indicates that both the microborings and the original oolitic laminae have formed under similar redox conditions controlled by marine chemical environments. The filling characteristics of the ooids differ significantly from those of the microborings and original laminae, suggesting an increase in oxygen content and indicating a more open diagenetic environment. Studying the features and genetic mechanisms of microborings enhances the understanding of microbe-carbonate rock interactions and provides new insights into the role of microorganisms in ooid formation, destruction, and micritization.</p>