The invention discloses an optical switch keyboard, including a circuit board and plural keys. The circuit board includes plural light emitters and plural light receivers. Each key is aligned with the corresponding light emitter and the corresponding light receiver. Moreover, each key includes a triggering element, a first reflective element and a second reflective element. When the triggering element is triggered by the user, a sensing light emitted by the light emitter is reflected to the second reflective element by the first reflective element. The sensing light is further reflected to the light receiver by the second reflective element. Consequently, the circuit board generates a key switch signal. In the optical switch keyboard, the light emitters and the light receiver are arranged out of the keys, so the key structure is simplified, and changing and adjustment are easy. A filter structure is arranged to filter other light rays and noise, and determination sensitivity and accuracy of the optical keys are improved.