A bicycle clutch comprises a transmission shaft, at least two gears, at least two slide blocks, at least two clutch blocks, at least two guiding blocks, a switch shaft and a stationary shaft. The gears and the slide blocks are coaxially disposed on the transmission shaft. The sliding blocks, switch shaft and stationary shaft are coaxially assembled. The clutch blocks are disposed on the transmission shaft, the gears and the slide blocks. The guiding blocks are disposed on the switch shaft and the slide blocks. Through angle deflection, the clutch can selectively make one of the gears engage with the driven assembly to change the rotation speed.