The present invention relates to a tool for preventing snoring and bruxism. Snoring and bruxism occurring during a sleep are prevented by using a flexible synthetic resin silicon structure which is integrally formed in a T shape and which is not harmful to a human body, and thus a sleeper can take a sleep while comfortably breathing. The tool comprises a body top part, a body front surface part, a body connection part, and a body bottom part. The body top part includes a tongue top compressing part formed on the top surface thereof to press the top of a tongue, includes an adsorber formed on the bottom surface thereof to adsorb the tongue to the tongue top compressing part, and includes a tongue top compressing part tail plate formed at the tail part thereof. The body front surface part has a connection part connected to the body top part, and has an air communication preventing plate which is installed at the end of the connection part, wherein the air communication preventing plate, when being inserted into the oral cavity, is disposed between the lips and the teeth to block communications of air in the oral cavity, thereby maintaining negative pressure in the oral cavity and supporting a main body not to be pushed to a rear side. The body connection part has a connection part for connecting the body top part and the body front surface part, and has a bruxism preventing plate which is installed at the connection part, wherein the bruxism preventing plate, when being inserted into the oral cavity at the top side of the air communications preventing plate, is disposed between the lower teeth and the upper teeth to prevent bruxism, and a tongue bottom support part is connected to the top side thereof to support the bottom of the tongue. The body bottom part has a tongue bottom support part connected to the body connection part and forked into two branches in a fork shape to support the bottom of the tongue. Also, a tongue root support having a thick thickness is incl
