The invention relates to an automatic cap-wearing device of plug-in tab splitters. The automatic cap-wearing device of plug-in tab splitters includes a workpiece positioning and clamping mechanism which is arranged on the device body for positioning and clamping a plurality of plug-in tab splitters, an arranging and conveying mechanism for arranging and conveying dust-proof caps in order, a movement mechanism for driving a material taking and interval separating mechanism to move in the horizontal and vertical directions, and the material taking and interval separating mechanism for taking outthe dust-proof caps from a material taking track and for automatic interval separating, wherein the workpiece positioning and clamping mechanism includes a positioning base and a quick clamp; the movement mechanism is connected with the material taking and interval separating mechanism; a cavity of an interval separating positioning base of the material taking and interval separating mechanism issuccessively decreased from the middle part to two sides in the horizontal direction and is provided with surfaces for horizontal spacing of interval separating blocks with different width, and the interval separating blocks whose width is decreased from the middle part to two sides successively are arranged in the cavity; the bottom of a gas pipe on each interval separating block is provided with a vacuum sucker; and a plurality of interval separating springs are arranged between every two adjacent interval separating blocks respectively. The automatic cap-wearing device of plug-in tab splitters has the advantages of being simple and reasonable in structure, being reliable in working, being able to reduce the labor intensity, and greatly improving the assembling efficiency and quality.