The invention discloses micro-alloying seamless pipeline steel and process for preparation. According to weight percentage, the range of the chemical components of the invention includes that C holds 0.08% to 0.20%, Si is equal to or less than 0.04%, Mn takes 0.60% to 1. 50%, S is equal to or less than 0.015%, P is equal to or less than 0.025%, Al is equal to or less than 0.04%, Ti is equal to or less than 0.04%, H is equal to or less than 2.5*10-4%, O is equal to or less than 25*10-4%, the rest is Fe and unavoidable foreign matters. The process for preparation comprises technique steps, including smelting, refining, continuous casting, hot rolling and slow cooling. Round steel with the size of phi 70 to 150 millimeters can be produced by the process for preparation. The seamless pipeline steel of the invention has perfect anti-sulphide stress corrosion (SSC resistance) capability and anti-HIC property. The pipeline steel which can substitute for welding pipe can be utilized in the filed of oil pipeline and the like, and the invention increases the reliability of material and adaptability of variety, in particular being adaptable for the low submarine temperature and corrosion-resistant environment and for manufacture of thick-walled tubes.