Casting method for thin-wall casting and special-shaped section pipeline sand core

The invention discloses a casting method for a thin-wall casting, which comprises the following steps of firstly, fixing a process core head on a special-shaped section pipeline sand core with a thin-wall casting sand core in an inserting and matching manner to obtain a casting blank, then heating the casting blank to scatter the special-shaped section pipeline sand core, removing the special-shaped section pipeline sand core in a special-shaped section pipeline through a process hole, then placing the welding blocking piece in the process hole and conducting welding to block the process hole, and finally, removing redundant welding blocking pieces and welding structures on the surface of the casting blank through polishing or cutting, and acquiring the thin-wall casting. According to the scheme, the strength of the special-shaped section pipeline sand core with the process core head is improved in the pouring process, the process hole is formed, then the process hole is blocked through the welding blocking p