An optical anti-shake apparatus with a switchable light path is furnished in an optical system having two light paths of different directions. The optical system also comprises a lens module, an image capturing module, an anti-shake device and a switching device. The lens module corresponds to the image capturing module in position. The switching device comprises a fixing member, a rotary member and a driving module. The rotary member is pivotal about the fixing member. The driving module is located between the rotary member and the fixing member. The anti-shake device is located on the rotary member such that the driving module can drive and rotate the rotary member together with the anti-shake device in order to perform switching operations, and thereby the light of either of the two light paths can be directed toward the lens module so as to focus at the image capturing module.