Abstract: According to a long period a hard quantiative of the visual est and other problems existed in the availabe thermal taility measuring method of the emulsion appied to the ihydrauic powered support.based on the data of the paricle size compositon.a study was conducted on the fe astblity to set up a rapid thermal stability measuring method of the emuision appied to the hyoraulicpowered support.The paricle size comp.sitin of the two dfferent emulsions appied to the hydraulic powered supprt was fested and measured.a setilement height of the oil paricle was calculated and a comparison was conduced withth ail soap slice thickress measured with the avallble measuring metod.The experinent resuts showved that with the data of the paric e composition.the setilenent height of the oly paricle was calculated and thus the method to measure the thermal stability of the emulsion applied to the hyaraulic powered support was feasibe.The settemert hegh ofthe iy article was related to the thermal stabiliy of the emulsion applied to the hydrauli: powered suppor.The igher the setlemert eight was,the pooer themal stailit of the emulsion applied to the hydraulic powered support would be and the lower settement height was.the better emusion themal s aiit appiedto the hyraulic: oweed support would be.