A suit of on-line test equipment based on electrochemical sensor was used to determine detonation gaseous products of a thermo-baric warhead. The arrangement and protection of the equipment was investigated, and the concentration-time curves of gaseous products in thermo-baric warhead detonation were obtained. The anoxia asphyxia effect and the miasma asphyxia effect were proposed and calculated. Detonation gases determination results of three kinds of charges show that the anoxia asphyxia and miasma asphyxia effects of thermo-baric warhead are stronger than that of normal charge, and the anoxia asphyxia effect is more obvious than CO miasma asphyxia effect.