According to an embodiment of the present invention, in order to perform fine particle agglomeration by outputting a low frequency sound wave and then remove fine particles, there is provided a method for fine particle agglomeration, the method including: an initial fine particle measuring step of generating fine particle measurement data including a pollution level of fine particles in a purification region and outputting the data to a sound source converting unit, by a fine particle measuring unit; a low frequency and sound pressure data extracting step of extracting a low frequency and sound pressure of a low frequency sound source stored in a storage to be used for agglomeration of fine particles, based on the fine particle measurement data, by the sound source converting unit; a sound source converting step of converting an output sound source into the low frequency sound source such that the low frequency sound source has the extracted low frequency and sound pressure data, by the sound source converting unit; and a fine particle agglomeration performing step of causing fine particles to agglomerate by receiving the low frequency sound source and outputting the low frequency sound source as a low frequency sound wave for agglomeration of fine particles, by a low frequency sound wave generating unit.