A laser alignment device with at least one movable mirror, a laser-target alignment sensor with movable mirrors and a laser alignment method are disclosed. The laser alignment device with the movable mirror comprises an image acquisition means for collecting incident lasers, a moveable mirror for reflecting the lasers to the image acquisition means and is operable to move linearly with respect to the image acquisition means, and a lens for forming an image of a target in the image acquisition means. The present disclosure achieves linear motion of the movable mirror with high accuracy in a small range, which in turn achieves fast and accurate alignment of the laser. It solves the problem of laser spots overlapping, reduces alignment time and improves shooting accuracy.