The invention relates to the technical field of linear cutting machines, and discloses a mobile linear cutting method and a mobile linear cutting machine. The mobile linear cutting machine comprises a device for processing work pieces different in thickness, a device for moving a linear cutting machine body, and the machine body; the machine body comprises a linear cutting working platform 13 and a linear cutting mobile platform 14; the linear cutting mobile platform 14 is in transmission connection with the linear cutting working platform 13 through guide rails 6 and a ball screw 15; the upper part of the linear cutting working platform 13 is provided with the device which is used for processing work pieces different in thickness and has a translation adjustment function; the lower part of the linear cutting mobile platform 14 is provided with the device for moving the linear cutting machine body. Processing can be implemented on certain heavy work pieces difficult to move by the mobile linear cutting machine disclosed by the invention; the bottom part of the linear cutting machine body is additionally provided with hydraulic drive castor travelling mechanisms, so the machine can be moved to the work pieces from optional directions, and is positioned rapidly for implementing the processing.