The invention provides a three-coordinate 
galvanometer scanning 
laser processing head, which comprises an XY two-axis 
laser galvanometer system, a clamping mechanism, a Z-axis moving mechanism, a 
laser displacement sensor and a 
control system, wherein the Z-axis moving mechanism comprises a fixed part and a moving part, and the clamping mechanism is fixedly mounted on the fixed part of the Z-axis moving mechanism; and the XY two-axis laser 
galvanometer system and the laser displacement sensor are fixedly mounted on the moving part of the Z-axis moving mechanism, and the laser displacement sensor, the Z-axis moving mechanism and the XY two-axis laser galvanometer 
system are all electrically connected with the 
control system. The 
laser processing head has the function of dynamic 
focal length setting, and has an independent and compact structure; the 
laser processing head has the broach 
interface design of a standard numerically-controlled 
machine tool, which enables the 
laser processing head to be easily assembled for 
processing with commercialized multi-axis synchronous numerically-controlled 
machine tools of a three-axis type, a five-axis type, and the like; and technological flexibility is greatly enhanced, and a conventional multi-axis synchronous numerically-controlled 
machine tool can be conveniently changed into a galvanometer scanning laser 
processing machine tool with compatible functions, thereby the three-coordinate galvanometer scanning laser processing head has important practical value.