The invention relates to a portable normal-voltage glow discharge micro plasma spectrograph and an application method thereof. The portable normal-voltage glow discharge micro plasma spectrograph mainly comprises a sample introduction system, an excitation light source, a detection system, a power supply system and a control display system, wherein the excitation light source is normal-voltage glow discharge micro plasma which is capable of maintaining stable glow discharge micro plasma at normal voltage; and the normal-voltage glow discharge micro plasma is driven by a direct-current high voltage and mainly comprises a high-voltage module, a light sensitive feedback module, two solid electrodes, a quartz sleeve and a plastic sealing sleeve. Due to adoption of the normal-voltage glow discharge micro plasma as the excitation light source, minimized portable development requirements of spectrographs can be met very well, the portable normal-voltage glow discharge micro plasma spectrograph has the characteristics of being good in stability, high in sensitivity, high in efficiency, small in size, low in cost, good in environment friendliness, and the like, and rapid detection requirements on metal and nonmetal elements in on-site analysis can be met.