The invention discloses an eight-tube storage unit capable of automatically adjusting the strength of a transmission tube and the strength of a pull-down tube. Two NMOS (non-channel metal oxide semiconductor) tubes capable of adjusting the strength of the transmission tube and the strength of the pull-down tube are added on the basis of a standard six-tube storage unit so as to realize the eight-tube storage unit which is capable of automatically adjusting the strength of the transmission tube and the strength of the pull-down tube according to types of reading and writing operation. When the storage unit is used for writing operation, the strength of the transmission tube is strengthened, writing noise margin of the storage unit is increased, and the speed of writing operation is increased. When the storage unit is used for reading operation, the strength of the pull-down tube is strengthened, reading noise margin of the storage unit is increased, and simultaneously, the speed of data reading operation is increased. The eight-tube storage unit has the advantages of high static noise margin, fine stability, fast reading and writing speeds and the like.