Abstract: A beer brewing device comprises: a mashing module, a boil and fermentation module, and a temperature control module. The boil and fermentation module is assembled with the mashing module in a swappable manner. The temperature control module controls the temperature of the beer brewing process. The boil and fermentation module can be detached from the mashing module during the fermentation process or after the beer brewing process is completed, such that another boil and fermentation module can be connected with the mashing module to perform another beer brewing process. In addition, the beer brewing device also has the advantages of automatic high-temperature cleaning and sterilization functions, two fermentation processes in one tank, and integrated and automatic brewing process.