A safety lancet for preventing reuse is provided, including an upper and lower case, moving block, guide, pressing plate, seating recess, and resilient spring. The upper case and a lower cases are coupled together with a space therein and a through-hole at the front to expose a lancet needle. The moving block is movable within the cases. with the lancet needle at the front. The guide is positioned behind the moving block within the cases and includes an anti-reverse ledge to selectively restrict reverse movement for reloading of the moving block. The pressing plate is pivotably mounted to the upper case and includes a stopper on which the moving block is caught, and a pressing projection for pressing the guide. The seating recess is defined in a bottom of the lower case, in which the guide descends and is seated. The resilient spring supports the rear of the moving block.
