The invention discloses a device and method for parallel mask-less scanning micro-nano processing based on an atmospheric pressure plasma jet tube. The processing device comprises the atmospheric pressure plasma jet tube and a jet nozzle tip array integrated at the lower end of the jet tube, wherein a three-dimensional precise movable platform is disposed on the lower part of the jet nozzle tip array; the jet nozzle tip array comprises multiple jet nozzle tips which are equipped with micro-nano holes; and each jet nozzle tip is equipped with a hollow micro chamber which is shaped like an inverted pyramid. The atmospheric pressure plasma jet tube is placed in an atmospheric pressure environment; reaction gases are continuously injected into the jet tube; ionization takes place to the reaction gases under an electric field effect, so that reaction plasma is generated; and the jet nozzle tip array is used to form a plasma nano jet flow array. The three-dimensional precise movable platform controls a plasma micro jet flow device to generate motion relative to a processed sample, so that low-cost, high-precision and efficient mask-less etching, sedimentation processing and surface modification can be implemented to multiple materials. In this way, requirements for processing and application of a small batch of micro-nano devices with multiple varieties can be satisfied.