The present disclosure relates to a method for high precision laser processing of sapphire with submicron-order section plane using a picosecond-order pulse laser which has high transmittance wavelength to sapphire. The laser triggers ultrafine phase transformation points or electronic state removal points from a lower surface of sapphire. After elevating focal points, a trace which is parallel to laser incident direction is formed. Under a chemical corrosion environment, points of the laser trace are arranged to intersect with other another according to the cutting route to form the corresponding phase transformation region and electronic state removal region. At the same time, by utilizing the catalysis effect of microthermal effect of picosecond laser on chemical corrosion, separation of the sapphire sample along the processing path is obtained. The present disclosure overcomes the limitation of Gaussian beam focusing mode and realizes high precision sapphire cutting with zero tapers and no heat-affected zone. Cutting of hyperfine sapphire and other materials with the high quality cutting surface in micron and submicron ranges with no limitation on the thickness and process path is achieved.