<p>The microstructures milled on tubes are so narrow that they can be damaged in deburring by conventional methods. In this study, an improved burr minimization method combined coatings and ultra-small-grinding (USG) for the top burr of the micro slot on titanium tube was proposed. The coating was prepared on the surface of the tube. Then, micro milling was used to mill a micro slot with a width of 200 μm on a tube, and big top burrs appeared during the process. After milling, a self-prepared USG tool with diameter of 100 μm was used to grind the root of the milling burrs for deburring by means of side grinding, replacing big milling burrs with tiny grinding burrs. During micro milling and grinding, the coating can suppress the formation of these machining burrs. Finally, the coating was removed, and the micro slot with tiny burrs on the tube was obtained. For the improved burr minimization method, a prediction model of the grinding burr size, considering workpiece shape, coating, and tool deflection, was proposed. Glue coating and a USG tool with a diameter of 100 μm were applied to validate experiments on TA2 tubes. The experimental results validated the effectiveness of the improved burr minimization method and the prediction model. Epoxy glue coating has the strongest inhibitory effect among the experimental coatings. The size of the grinding burr increases with the increasing feeding velocity. The structure losses of the micro slot on the tube induced by the USG tool with a diameter of 100 μm were captured, which are 8.75% width and 24.71% depth. Through EDS elemental analysis, the grinding zones of USG were divided into smooth, transition, and burn zones.</p>