The invention relates to a system for micropower wireless meter centralized reading communication based on dynamic adjusting of antenna gain directions. The system is characterized in that three groups of antennas are respectively arranged in a micropower wireless communication module in an orthogonal 90-degree way, and are respectively controlled by three paths of radio frequency switches; and the maximum radiation gain direction of synthetic receiving and sending antennas can be adjusted by software in real time according to the field actual conditions, so the path with highest signal-to-noise ratio is always used in the signal transferring between each pair of communication modules. The invention also relates to a communication method of the system. The system and the method have the advantages that the requirement of manually adjusting and optimizing the antenna directions in the field is fundamentally avoided; and the problem of communication caused by the position change of additional electric appliance equipment or metal objects in the use process is effectively solved, an optimum route topology graph of a micropower wireless communication local area network is dynamically optimized, and the self-healing capability for abrupt communication problems is realized.