In the established nanosecond pulse laser electrochemical machining (LECM) system, a compound processing method of laser and electrochemistry is used to process metals such as 304 stainless steel, 7075 aluminium alloy, 1060 aluminium and brittle materials like silicon under the same processing parameters. The mechanism of the laser thermal- mechanical effect on promoting electrochemical machining is investigated. The polarization curves of different materials are measured. The compound processing surface morphologies of different materials are comparatively analyzed by scanning electron microscope (SEM). A VHX- 1000 threedimensional super depth digital microscope is adopted to analyze the processing depths, widths and aspect ratios of different materials. The results indicate that under the action of laser thermal- mechanical effect, the electrochemical etching quality and surface morphology of aluminum alloy are better than those of stainless steel and aluminum. And relatively large aspect ratio microstructure can be processed. Besides, the shock calving of microparticle occurs to the brittle materials.