The invention discloses a device for the gas linear cutting of a silicon slice, which comprises a flow controller, a pressure reducing valve, a pressure gauge, a vacuum pump, a vacuum-cavity pressure gauge, a vacuum-cavity temperature control device, a vacuum chamber, a spray head, a masking plate, a silicon slice frame, a post pump and a tail gas processing device, wherein the pressure reducing valve, the vacuum pump, the vacuum-cavity pressure gauge, the vacuum-cavity temperature control device and the post pump are respectively connected with the vacuum chamber, gas enters the vacuum chamber after sequentially passing through the flow controller, the pressure reducing valve and the spray head, then the silicon slice on the silicon slice frame is cut through the masking and the beam convergence and regulation of the masking plate, the temperature of the vacuum chamber is controlled to be under a room temperature environment through the vacuum-cavity temperature control device, and etched tail gas is pumped out of the vacuum chamber through the post pump and enters the tail gas processing device through the post pump. In the invention, chlorine trifluoride is used as etching reaction gas for carrying out cutting processing for the silicon slice, and the problems existing in a traditional technology can be well solved.