For purposes of fingerprint identification, a fingerprint acquisition apparatus and method, a terminal device, and a method for controlling a screen to be on or off, are provided. The fingerprint acquisition apparatus includes: a fingerprint sensor, an optical sensor and a signal processing unit. The fingerprint sensor and the optical sensor connect to the signal processing unit, respectively. The optical sensor is configured to emit an optical signal and receive a reflected signal formed after reflection of the optical signal via a human finger. The signal processing unit is configured to activate the fingerprint sensor according to the reflected signal; and the fingerprint sensor is configured to acquire fingerprints of the human finger after being activated.