Manufacturing method of ultrahigh-precision 6-series aluminum alloy profile

The invention relates to a manufacturing method of an ultrahigh-precision 6-series aluminum alloy profile, which comprises the following steps: smelting and casting an aluminum alloy raw material to obtain an aluminum alloy round cast ingot, homogenizing the aluminum alloy round cast ingot, and sawing to obtain an aluminum bar for extrusion; the aluminum bar is subjected to extrusion forming to obtain an extruded profile, the on-machine temperature of the aluminum bar is 490-510 DEG C, the mold temperature is 460-480 DEG C, and the profile extrusion speed is 2.9-3.2 m/min. By controlling the content of each component of the aluminum alloy raw material, particularly strictly controlling the fluctuation range of Si, Fe and Mg alloy elements, combining a special processing technology, and particularly controlling the optimization of the on-machine temperature and the extrusion speed of the aluminum bar, the deformation resistance of the aluminum bar is relatively small, the extrusion is relatively easy, the infl