The invention discloses a planting plan optimization system and a method based on agricultural Internet of Things and a big data analysis. The system comprises a data acquisition and processing module, a database, a statistics processing module, a crop planting plan optimization model and a corresponding optimization engine, a central processor, and a computer decision auxiliary system, and the computer decision auxiliary system comprises a user interface and function module used for helping decision makers to compile executable crop planting plans, and a data interaction and interface module of a crop production and management system. According to the system and the method, based on the Internet of Things and supported by the informatization technology, a unified business information management platform is constructed, informatization management of various agricultural production links such as scientific research, production, logistics, and sales is realized, and reasonable planning of agricultural product planting and production, high efficiency production, scientific prediction, accurate sales, and data decision are realized.