In order to get the right lidar data, a well alignment of transmitter-receiver optical system is essential. To get right lidar data when the laser beam moves slightly, it is necessary to adjust the beam to the center of the telescope field of view. The laser sweeps the space describing a spiral in the plane at the beginning until a small part of the beam is detected by the telescope. Then a cross scanning of beam is presented to adjust the laser beam until it falls in the center of the telescope field of view. A dedicated software has been developed to execute the self-alignment procedure. The self-alignment of transmitter-receiver optical system can be accomplished with a single click.