Horizontal continuous casting crystallizer of cast iron and preparing method of cast iron proximate matter

The invention discloses a horizontal continuous casting crystallizer of a cast iron and a preparing method of cast iron proximate matter. The crystallizer comprises a crystallizer body; a collector nozzle type isolation ring is arranged at the front end of a high-purity graphite casting mold of the crystallizer body; according to the horizontal continuous casting crystallizer of the cast iron, the collector nozzle type isolation ring is arranged at the front end of the high-purity graphite casting mold, the blocking effect of the collector nozzle type isolation ring is used for forcing molten iron not to enter the high-purity graphite casting mold in a laminar flow manner, the molten iron must enter the high-purity graphite casting mold in a forced laminator flow manner, the high-speed washing effect generated by turbulent fluid flowing of the molten iron is sufficiently utilized, the molten iron is pushed backwards before being solidified, and the molten iron enters a forced cooling area of a water-cooled ir