The quality changes of paddy during storage are greatly affected by external conditions. The external factors include temperature, moisture, air proportion, pests and microorganisms, etc., especially under the condition of high temperature of stored grain and high moisture of rice, mold of rice grows faster, which leads to the reduction of rice quality. This paper introduced the effects of storage conditions on paddy quality and the harmfulness of pests and harmful microorganisms to paddy storage. The research on existing paddy storage and new grain storage technologies were further discussed. The development of new technologies such as grain storage, the use of CO2 to detect rice mold, and the development of natural antifungal agents has provided more effective technical guarantees for the safe storage of paddy in our country. However, some new technologies have higher requirements on grain silos and it is difficult to realize nationwide popularization.