The invention discloses a production technique of andrographolide and neoandrographolide, dehydroanddrographolide and oxyandrographolide; the technique comprises the following steps of: firstly preparing stem and leaf extract of andrographis paniculata, removing fat-soluble impurities such as chlorophyll and the like with petroleum ether, and then hot-melting the extract in lower alcohol or aqueous lower alcohol, conducting reflux and decolorization with active carbon, separating out a majority of andrographolide crystals, then removing flavonoid through an alumina column or alkali cleaning, obtaining the andrographolide, cold-melting the andrographolide with trichloromethane or dichloromethane for 2 to 4 times, filtering and obtaining two parts of filtrate and insoluble substances, concentrating the filtrate, then conducting solvent crystallization and recrystallization or column chromatography for separation, and finally, respectively obtaining dehydroanddrographolide and pure product of andrographolide; the insoluble substances go through solvent crystallization and recrystallization or column chromatography for separation to obtain the neoandrographolide and pure product of andrographolide. The technique has simple production equipment, simplified routes and easy operation, can realize industrialized batch production; and the proportion of neoandrographolide, dehydroanddrographolide and oxyandrographolide in the obtained andrographolide is high, while the content of impurities is low. The obtained neoandrographolide, dehydroanddrographolide and oxyandrographolide all have monomer purity of higher than 98 percent, thus being capable of being used as chemical reference substance of the traditional Chinese medicine, or being applied as raw materials of medicine and chemical industry.