Hemp belongs to the industrial hemp category currently allowed to be grown in China, which is completely different from the drug marijuana that is widely abused in Europe and the United States. The active ingredient in hemp is mainly cannabidiol (CBD), which has no psychoactive properties, while the content of tetrahydrocannabinol (THC), which has hallucinogenic and addictive effects, is less than 1% and is rarely used as a drug. Despite this, in order to prevent the proliferation of drug cannabis, many countries currently limit the THC content in industrial hemp. Among them, the EU standard has been widely adopted, that is, the THC content in dried industrial hemp must be controlled below 0.3%. Our country also adopts this standard when developing industrial hemp.