In order to improve the high-temperature resistance of powder emulsion explosive,the super absorbent polymer(SAP) after absorbing water was added.Then the temperature rise curves of the mixed explosive in the high-temperature blast holes were measured by thermocouple,and the detonation velocities of the mixed explosive in the blast holes were measured by corresponding instrumentation.The results show that the SAP after absorbing water can absorb heat and release water vapor in the high-temperature blast hole,which greatly reduces the temperature-rising rate of the mixed explosive due to the large specific heat capacity of water.In addition,since the SAP after absorbing water will secrete water after mixed with the powder emulsion explosive,the mixed explosive is heated evenly and can be maintained below 100℃.The heat resistance of the mixed explosive is significantly improved with the increasing of the SAP content.Because the density of the mixed explosive is higher than that of the normal powder emulsion explosive,the detonation velocity of the mixed explosive containing 10% SAP is equivalent to that of the wet powder emulsion explosive(3980 ms-1),and is 6% to 11% higher than that of the powder emulsion explosive(3733 ms-1),even though the SAP will absorb heat and hinder the propagation of detonation waves during detonation reaction.With the gradual increase of the SAP content,the detonation velocity of the mixed explosive decreases greatly and even fails to explode,and the particle size of the SAP has a significant effect on the detonation velocity.By comprehensive consideration,SAP with particle size of 10 mm accounting for 10% of to the powder emulsion explosive is a better choice,which can not only improve the safety of the mixed explosive in high-temperature blast holes,but also does not affect the explosive power of the mixed explosive.