The utility model provides a prepare high -purity liquid hydrogen cyanide system, a serial communication port, including the absorption tower, the syllogic rectifying column, well intercooling congeals the ware, direct condenser, a gas -liquid separator, the finished product condenser, the reboiler, the absorption tower is equipped with the low warm water in top and sprays the mouth, top tail gas discharge port and contain the gaseous inlet port of hydrogen cyanide, the syllogic rectifying column divide into the upper segment tower, the middle section tower, the hypomere tower, be connected bottom the absorption tower with between hypomere tower and the middle section tower, the head tower bottom is equipped with the reboiler down, intercooling congeals the ware in being equipped with between upper segment tower and the middle section tower, syllogic rectifying column top is equipped with direct condenser, direct condenser and vapour and liquid separator are connected, vapour and liquid separator is connected with the finished product condenser. The utility model discloses a low temperature water uptake has improved the gaseous absorption efficiency to HCN, has alleviateed the load to follow -up tail gas treatment facility, has alleviated environmental protection pressure, finished product hydrogen cyanide water content can reach below the 50ppm, more is favorable to the safety in production, and improves the production efficiency.