The grain storage process could be affected by many aspects such as biological field and non biological field, which will lead to the phenomenon of heating, mildew, dewing and pest damage in the grain storage process. It is urgent to develop convenient, fast, multi-functional and high-precision on-site detection tools. According to the requirements of actual grain storage management, the multi-functional grain storage safety on-site rapid detection analyzer could calculate the stored grain moisture, water activity, absolute humidity, accumulated temperature, accumulated humidity, J/Q value and absolute water potential with models and algorithms on the basis of multi-point high-precision detection of temperature, humidity and CO2 concentration, and could graphically expresse the calculated results to assist in the determination of stored grain conditions such as safety, condensation, heat, mildew, etc, which will have mechanical ventilation operation parameter selection and intelligent control. The preliminary application of the instrument shows that it can provide effective technical support for granary management and has a good application prospect.