A 400 nm femtosecond laser was used to ablate the surface of a high-pressure and high-temperature diamond,and subwavelength surface micro structures with a period of 100 nm were achieved.A variety of micro-nano composite surface structures were prepared by changing the polarization direction and laser scanning direction.By dynamically adjusting the laser polarization and the laser scanning tracks,a maskless direct writing fabrication of micro-nano complex structures was realized.The micro-nano patterning on an ultra-hard and super-stabile diamond provides a new idea for the preparation of friction reducing surfaces,nano imprint transfer templates,surface enhanced Raman scattering test substrates,and micro-nano optical structures.