The invention discloses a rapid clamping and casting mechanism applied to the field of casting. The rapid clamping and casting mechanism comprises a base, a mold with a casting port at the top is fixedly mounted on the base, a sleeve for placing the mold is rotatably mounted at the top of the base, a plurality of through grooves are formed in the outer side of the sleeve, sliding sleeves are rotatably mounted in the through grooves, first connecting rods slidably connected with the sliding sleeves are rotatably mounted at the top of the base, and the free ends of the multiple first connectingrods are rotatably connected with rollers tangent to the surface of the mold. According to the rapid clamping and casting mechanism, when the sleeve rotates clockwise, the first connecting rods are driven to rotate outwards relative to the mold, the mold is loosened and taken out conveniently, when the sleeve rotates anticlockwise, the first connecting rods are driven to rotate inwards relative tothe mold, the mold is clamped, the mold is fixed conveniently, meanwhile, automatic centering of the mold can be achieved, it is guaranteed that the central axis of the mold and the central axis of the sleeve are collinear, therefore, accurate communication between a casting funnel and the casting port is guaranteed, and molten iron splashing or overflowing during casting is avoided.