Flexible positioning device for core setting of large sand core and sand core applying same

The invention relates to a large sand core setting flexible positioning device which comprises a light source emitter and an observation assembly, and the light source emitter is arranged on a sand mold; a guide hole is vertically formed in the sand core in a penetrating mode, and the observation assembly is arranged at the end, away from the sand mold, of the guide hole; the light source emitter, the guide hole and the observation assembly are coaxially arranged, and light beams emitted by the light source emitter penetrate through the guide hole to reach the observation assembly. The invention further relates to a sand core adopting the flexible positioning device for core setting of the large sand core for core setting positioning. According to the flexible positioning device for core setting of the large sand core, the defects that a core head collides with a sand mold, sand is included, the wall thickness size is unqualified and the like due to inaccurate core setting are overcome; the sand core and the