The invention discloses a granary storage condition detection system comprising a single-chip microcomputer control center, a power supply module, an A/D converter, multiple granary detection units, a displayer, an external memory, a timer, a GPRS module and an electric power carrier communication module. Multiple granary detection units acquire reserve information of different granary positions and output analog signals to the single input end of the A/D converter. The signal output end of the A/D converter is connected with the single-chip microcomputer control center. According to the granary storage condition detection system, moisture detection, temperature alarm and granary reserve information detection are integrated so that the structure of the system can be simplified, the granary internal data are summarized and processed through the single-chip microcomputer, two information transmission modes of wireless communication and wired communication are simultaneously arranged, wired communication is realized by using the electric power carrier communication technology and thus the cost of line laying can be saved and the system has the advantages of diverse functions, accurate control and high practicality.