Disclosed are a clutch device, a drill chuck, a power tool, and a bidirectional rotation method of the drill chuck. The clutch device comprises a return elastic member, a transmission assembly and a rotating portion, wherein the transmission assembly comprises at least two oppositely arranged engagement portions; the engagement between the two engagement portions enables a front body and a rear body to rotate synchronously; the rotation of the rotating portion in a first direction enables the return elastic member to be compressed, such that the two engagement portions are disconnected; and the rotation of the rotating portion in a second direction enables the compressed return elastic member to return to an initial position such that the two engagement portions are engaged. The drill chuck comprises a front body, a rear body, clamping jaws and the clutch device; and the power tool comprises a driving shaft and the drill chuck.