Disclosed are dihydropyrimidine compounds and preparation methods, pharmaceutical compositions and uses thereof. Specifically, the compounds described herein in general formula (I), or their isomers, pharmaceutically acceptable salts or hydrates are provided, wherein each variable has the meaning as defined in the description. Also provided are a process for preparing the compounds of the general formula (I), the use of the compounds, an isomer thereof, a pharmaceutically acceptable salt thereof or a hydrate thereof as a medicament, in particular as a medicament for the treatment and/or prevention of Hepatitis B.