Laser machining system and method for a laser machining system

A method for centrally aligning a laser beam in a machining head of a laser machining system for machining a workpiece using said laser beam, comprising:

• providing said machining head with a housing having an opening for emitting said laser beam from said machining head;
• directing an optical measurement beam onto an optical unit for aligning said laser beam and said optical measurement beam;
• adjusting said optical measurement beam in at least one direction perpendicular to an optical axis of said machining head in a region of said opening by means of said optical unit;
• wherein adjusting said optical measurement beam includes setting said optical measurement beam to a first position such that said optical measurement beam does not pass through said opening and is reflected from an internal surface within the housing adjacent to said opening, and setting said optical measurement beam to a second position such that said measurement beam passes through said opening and is reflected on an external surface outside the housing;
• and
• measuring distances to the internal and external surfaces to provide measurement values based on reflections from the internal and external surfaces;
• and
• determining by a measuring device a setting of said optical unit corresponding to a central alignment of said laser beam in said at least one direction on a basis of measurement values based on the reflections of said optical measurement beam at said first and second positions.