Gunpowder was first invented by China people, and sulfur, one of the ingredients of gunpowder, was recorded in Huainanzi, a Taoist classic in the Western Han Dynasty. In Shennong's Classic of Materia Medica, sulfur and saltpetre are listed as top-grade drugs that can treat diseases. Nitrite is also a mineral, which is produced in Sichuan and Gansu provinces. It is a strong oxidant, which can release oxygen when heated, and it is easy to smoke and get angry, so it is also called smoke nitrate or fire nitrate. Because saltpeter is very active in chemistry and can react with many substances, alchemists often use saltpeter to change the properties of other drugs in alchemy.

During the Western Han Dynasty, Chunyu Kun treated Wang Mei's disease with saltpeter. In the long-term practice of alchemy, alchemists constantly mixed and calcined saltpeter, sulfur, realgar, turpentine, grease, charcoal and other substances, making the invention of gunpowder inevitable.

The alchemists also made "experimental" observations and studies on various characteristics of sulfur. They found that sulfur can not only react with copper and iron, but also subdue the magical mercury. Sulfur is very active in chemistry. It easily catches fire and reacts with oxygen in the air, which makes it difficult for people to control it. In order to tame its violent character, the ancients tried to "subdue" the fire of sulfur.

The so-called "reducing fire" is originally a method of treating diseases. According to the theory of Yin-Yang, Five Elements and Dirty Meridian in TCM, alchemists believe that saltpetre and sulfur are both Yang (because they can both catch fire), which will have the poison of Yang fire and can defeat people's five internal organs. In order to make people not only have no toxicity after taking it, but also nourish the five internal organs, so that the qi of the five internal organs in the human body can be mixed harmoniously and help to prolong life, we must try to subdue the fire poison, which is called "reducing fire", and the specific method of "reducing fire" is also very simple, that is, "fighting poison with poison". If you burn it with fire, the poison of the fire will be eliminated naturally.

In the practice of alchemy, alchemists gradually found that sulfur, saltpeter and charcoal were mixed together, which would cause combustion or even explosion if it was not done well. This kind of situation happens much more, which will naturally attract the attention of alchemists. So someone specially did this kind of experiment, accumulated experience and improved the formula. Because sulfur and saltpeter are both medicines that can cure diseases, and because they will get angry when combined with charcoal, people call the mixture of these three things gunpowder, which means "medicine that gets angry". Because the color of this mixture is close to black, it is often called black powder.

The earliest record about the formula and combustion of black powder comes from the book "The Method of Sulfur Content in Single Crystal" written by Sun Simiao, a famous Chinese medicine doctor, "the King of Medicine" and a health care practitioner in the early years of the Tang Dynasty. This is also the earliest record of the original formula of light industrial powder in the world. It describes the method of reducing sulfur: bury the sand pot or silver pot in the soil, and the pot mouth or pot mouth is flush with the ground. The surrounding area should be tamped with soil, and two nitrate and sulfur should be put. Then burn three branches of Gleditsia sinensis. Don't burn them to ashes, just burn them to charcoal, and then put them in the pot or pot one by one. At this time, the freshly burned honey locust comes into contact with saltpeter and sulfur with residual fire, and the saltpeter and sulfur will burn automatically. After the flame smoke is burned out, pile charcoal on the jar mouth and heat it to get a formula of black powder. Here, the three main components of black powder are ready: nitrate, sulfur and carbon. The reaction is not intense enough, just because the carbon has not been ground and mixed with nitrate and sulfur sufficiently and evenly. In addition, the purpose of "lying on fire" is to prevent and avoid violent combustion and explosion, and some measures only make purple fireworks appear after the reaction burns.