The invention provides a no-debugging miniature laser device ignition device and method. The laser device ignition device comprises a pyramid prism, a columnar light-gathering cavity, a pulse xenon lamp, a laser crystal rod, Q-switched crystals and a laser output film. The resonant cavity of a laser oscillator is formed by the pyramid prism and the laser output film. Light emitted by the pulse xenon lamp is gathered by the columnar light-gathering cavity and then incident to the laser crystal rod. The laser crystal rod absorbs pumping energy and generates oscillation laser between the pyramid prism and the laser output film. The laser is modulated into a pulse mode through the Q-switched crystals and then outputted out of the resonant cavity through the laser output film. The no-debugging laser resonant cavity is formed by utilizing backward reflectivity of the pyramid prism so as to suppress laser ignition vibration environment. The laser crystal rod, the Q-switched crystals and the laser output mirror are integrally designed and processed as a whole so that the no-debugging and miniature and practical characteristics of an ignition laser device can be realized finally, and thus the method is simple and practicable.