The invention discloses steel for a high-pressure pipeline valve and a manufacturing method of the steel. The steel for the high-pressure pipeline valve comprises components in percentage by weight as follows: 0.19%-0.23% of C, 0.15%-0.25% of Si, 0.95%-1.10% of Mn, smaller than or equal to 0.30% of Cr, smaller than or equal to 0.40% of Cu, smaller than or equal to 0.020% of S, smaller than or equal to 0.020% of P, smaller than or equal to 0.40% of Ni, smaller than or equal to 0.12% of Mo, 0.010%-0.040% of Ti, smaller than or equal to 0.03% of V, smaller than or equal to 0.02% of Nb, 0.015%-0.025% of Al, smaller than or equal to 15*10<-6> of O, smaller than or equal to 90*10<-6> of N and the balance of Fe and inevitable impurities. Through content control of carbon and manganese elements, the mechanical property requirements of steel are guaranteed, meanwhile, the content of residual elements is controlled, the material welding property requirement is guaranteed, the fatigue strength of steel is enhanced, and the valve stability is guaranteed. Through control of molten iron (or pig iron) mixing proportion, furnace slag refining amount, VD (vacuum degassing) furnace operation and reinforced water gap protection and casting effect, titanium is added for nitrogen fixation, and the nitrogen content can be controlled below 90 ppm.