The invention discloses a laser-induced breakdown spectrometer for multi-sample detection, which comprises a sample adding chamber, supporting legs, an observation window, a sample placing and takingcover, a fixed shaft, a rotary detection disc, a placement groove, a detection chamber, a focusing lens, a laser head, a receiving coupling lens, an optical fiber chamber, a spectrograph body, a computer, a self-return type sample pressing and cutting blade structure, an adjustable sample surface cleaning hair structure and a post-detection sample collecting and filtering protective box structure,wherein supporting legs are longitudinally connected to the four corners of the bottom of the sample adding chamber through bolts, the observation window is embedded in an observation opening in theright side of the sample adding chamber, and the sample placing and taking cover is connected to a left placing opening of the sample adding chamber through a movable bolt. Through arrangement of a self-return pressing seat, a U-shaped lining seat, a cutting table, a self-return spring, a cutting motor and a cutting blade body, cutting of a to-be-detected sample is facilitated, so that the detection convenience is guaranteed, and the detection requirement is met.