The invention provides a method for enabling laser to induce metal target plasma to achieve ignition of flammable gas and a device for achieving the method, and relates to the method for achieving ignition of the flammable gas and the device for achieving the method. The method and the device for achieving the method solve the problem that an existing method for enabling laser to directly breakdown the gas to induce the plasma to conduct ignition is high in minimum ignition energy, low in ignition success rate and high in requirement for laser output energy. The method includes the steps of enabling premixed gas to enter a quartz tube, emitting a laser bundle through a Nd:YAG laser, focusing the bundle on the surface of a metal target, inducing the metal target to produce the plasma and igniting the premixed gas in the quartz tube. According to the device, the gas outlet of a premixing tank is communicated with the tail end of the quartz tube, the metal target is arranged on the side face, above the tube opening of the quartz tube, of the quartz tube, laser produced by the Nd:YAG laser is reflected to a spectroscope through a mirror and divided into reflected light and transmission light through the spectroscope, the first reflected light is emitted outward, and the transmission light penetrates through a lens and is focused on the metal target through the lens. The method and the device are suitable for situations where flammable gas ignition is needed.