Phase transition of quartz is widely used in the high pressure experiment as the standard of pressure correcting of the laboratory instrument. And the quartz is usually used as the pressure sensor in the experiment when the pressure is low. Christian S et al discussed the function between the pressure and the shift of quartz's Raman spectrum peak when the shift isn't exceeding 20 cm(-1). In order to extend the applying range, the authors discussed the function again using the diamond anvil cell, and used ruby as the pressure sensor which is widely used in the high pressure experiment. After discussing the function, we obtained a new function that is P(MPa) = -1.094 83E7 + 67 495.237 31 X DeltaV-138.706 91(DeltaV)2 + 0.095 04 (DeltaV)3 which is different from the Christian's function.