Preparation of silkworm eggs is an important link in sericulture production. As early as the Qin and Han dynasties, people knew that proper high temperature and satiety were beneficial to the growth and development of silkworms and could shorten their age. Therefore, all previous dynasties paid great attention to controlling the adjustment of humidity and temperature in sericulture environment. According to Qi Shu Yao Min, people put a fire around the silkworm house to adjust the temperature of the silkworm house. In Yuan Dynasty, The Scholars Must Use pointed out that when young silkworms are born, the silkworm house should be warmer because it was still cold. And it will be cooler after sleeping, because it was already very hot at that time. After long-term sericulture practice, ancient silkworm farmers have accumulated rich experience in silkworm disease prevention and control. More than 2000 years ago, the ancients in our country knew to wash the egg noodles with clear water bath, and later it was further developed to dissolve and disinfect the egg noodles with drugs with disinfection effects such as cinnabar solution, salt water and lime water. This is very important to prevent silkworm diseases.

1400 years ago, the ancients in China paid attention to the selection of silkworm eggs. Qi Yao Min Shu puts forward that we should choose the quality of cocoon, the time and place of cocoon formation, the time of moth cocoon emergence, the health status of moth and the health status of eggs. Choose cocoon, moth and egg. In the Qing dynasty, people paid more attention to the choice of silkworms. They know that only "silkworms are disease-free, and species are disease-free". Through strict seed selection, a large number of weak and sickly silkworm eggs were eliminated, thus improving the physique of the second generation of silkworm, and at the same time, it is beneficial to prevent microparticle bacteria from being transmitted to future generations through embryos to some extent.

In order to develop silk production, in ancient times, in addition to raising silkworms, summer silkworms and autumn silkworms were also raised, and even many batches of silkworms were raised a year. Li Zhou has a record of "original silkworm", and "original" means "again". "Protosilkworm" is the second silkworm raised in a year, that is, summer silkworm. According to the Records of Yongjia County edited by Liu Song and Ji Zheng, Yongjia (now Wenzhou, Zhejiang) could raise eight batches of silkworms a year in the 4th century. As we all know, silkworms are different from unisexual, bisexual and polygamous. In tropical areas (such as Guangdong Province), polyploid silkworms can be naturally hatched for many times in one year to raise many batches of silkworms, or eggs laid by diploid silkworms can be made green at a proper low temperature, so that the laid eggs can continue to ovulate in the same year. If we continue to keep the low temperature and promote green growth, we can continue to hatch and raise many batches of silkworms a year. This is really an amazing invention.

In the production of summer silkworm eggs in Ming Dynasty, the heterosis of silkworm was also found. Song said in "Heavenly Creations" (1637): "There are some people in the cold race today, and they have a beautiful species and are different." The so-called "early males and late females" means that male silkworms and female silkworms cross to produce "fine varieties", that is, excellent silkworm eggs. This is the earliest record about the utilization of silkworm heterosis in the world.