The invention belongs to the technical field of tubing steel manufacturing, and particularly relates to a steel material for a CT80 level coiled tubing and a manufacturing method thereof. The steel material comprises the following chemical components in percentage by mass: carbon: 0.11 to 0.13%, silicon: 0.30 to 0.40%, manganese: 0.70 to 0.90%, chromium: 0.50 to 0.60%, nickel: less than or equal to 0.25%, Mo: 0.13 to 0.15%, copper: 0.30 to 0.40 %, niobium: 0.02 to 0.04%, and the balance being iron and inevitable impurities, wherein nitrogen is less than or equal to 0.004%, phosphorus is less than or equal to 0.015% and sulfur is less than or equal to 0.005% in the purities. The manufacturing method comprises the following steps: the alloy is smelted, a solid core metal calcium cored wire is used for final deoxidation in the smelting process, and then the controlled rolling and controlled cooling rolling is carried out after an ingot is formed, and the finished product is a 4.5mm strip. The steel material provided by the invention has the advantages of complete deoxidation, fine grain and uniform microstructure, and better yield strength, elongation and hardness value.