Inner insert fast cooling pressure casting die

The invention relates to an inner insert fast cooling pressure casting die which comprises an upper die plate and a lower die plate. An upper die core and a lower die core are arranged between the upper die plate and the lower die plate. An inner shaft core is installed in the middle of the lower die core in an embedded manner, and a forming insert bush is coaxially arranged on the outer side of the inner shaft core. Multiple inner groove forming protruding parts are arranged at the upper end of the forming insert bush, and cooling water pipe sets are symmetrically arranged in the forming insert bush left and right. Each cooling water pipe set comprises a water inlet pipe and a water outlet pipe which are vertically arranged side by side, wherein the upper end of the water inlet pipe communicates with the upper end of the water outlet pipe through a first-layer arc water pipe and a second-layer arc water pipe which are horizontally arranged in the up-down direction, multiple U-shaped concave parts are arrange