Abstract: in order to reduce the time required to measure the gaspressure at the ste,the paper discussed the passive mode pressure measured method.The theoretically analyzed the radius of the pressure measured borehole and the depth in coal af cted to the time reured to measure the gas pressure Acalculation model wa.esablis hed and a tormula was derived tocalcuate the measurig stable timeof the gasprssure. Theresuts showed tht the measuring stabl time of the seam gas pressure would be directly proprtional to 4 / 3 power of the pressure measuring borehole radius and would be diesctly proortihnal t 2 3 pover of the depth in the coaof the pressure measured borehole.The stie testresults showed that under the same borehole expose time, the smale of the borehole radius and the deth in co l,theless measuring time of the gas pressure woud be and the higherof the gas pressure measuredresuts would be .Mfeanwhile,the fe astilit of the theoreical fomu a wasexpressed and thus could provide the important reference basis to the rapid measurement of the seam gas pressure.