Curved electronics, which are better coordinated and blended with the natural world due to the characteristics of large contact area, high space adaptability, etc., have been widely used in a quantity of areas ranging from conformal curved antennas and sensors in detection and measurement, to artificial smart skin of aerospace. Recent developments in curved electronics have made an increasing progress to the historic drawbacks of conventional planar electronics, however significant challenges still exist. Here, the main kinds of conformal fabrication technologies, including transfer printing, assembly techniques, curved lithography, conformal inkjet printing, 3D printing, and laser direct writing, are reviewed to realize manufacturing deformable/undeformable electronics on curved or arbitrary surfaces. The processes and features of each technology are comprehensively summarized together with their progress and potential values. Finally, the challenges and opportunities for fabricating conformal electronics on arbitrary surfaces are also discussed.