Abstract: In order to solve problems of coal-fired pollution，high energy consumption，bad control and lower drying quality problems in normal grain drying systems，large scale heat-pump grain drying system was designed and optimized.According to special structure of drying tower of this system，finite element structure analysis and dynamic analysis method of extreme load boundary condition were adopted to designed and analyzed structural strength and dynamic stability of grain drying tower，problem that drying tower was too large to be tested and analyzed was solved.Test results showed that heat-pump grain drying system could achieve efficient and stable operation at low temperature environment of -30℃，that design goal was achieve.Heat-pump grain drying tower could meet relevant technical requirements for industrial application.