Microdrum sizing tool

The invention relates to a microdrum sizing tool. The microdrum sizing tool comprises a first base, a limiting and hooping sleeve, an extrusion mandrel, a microdrum limiting sleeve, a guide post, a second base and a spring, wherein the limiting and hooping sleeve is mounted on the first base; the extrusion mandrel is positioned in the limiting and hooping sleeve; the microdrum limiting sleeve is mounted on the second base; the guide post is positioned between the limiting and hooping sleeve and the microdrum limiting sleeve; and the spring is arranged on the guide post. When the spring is compressed, the extrusion mandrel enters a microdrum hole for extruding and sizing the microdrum.