The invention relates to cold shortness resistant N80 petroleum pipe steel and a manufacturing method thereof. An electric furnace is used for smelting, the proportion of molten iron is not less than 60%, the content of end point C is 0.10-0.15%, and the content of P is less than or equal to 0.008%. The alkalinity of refining slag is 3.0-3.5. Before LF tapping, the target content of acid-solved aluminum in the steel is controlled to 0.015-0.040%, and a calcium line is fed by 1.0-2.5m in per ton of steel for calcium modification. Vacuum treatment is conducted after refining. Continuous casting is adopted for casting a blank, and a crystallizer is adopted for electromagnetic stirring and final electromagnetic stirring during continuous casting. The temperature of a tundish and the pulling rate are controlled, the heating soaking temperature is 1200-1250 DEG C, the heating time is 2-3.5h, the rolling temperature is 1100-1150 DEG C, the final rolling temperature is 850-1000 DEG C, so that the hot-rolled round steel is obtained. A steel pipe prepared from the steel has the advantage of excellent cold shortness resistance and can be applied to the petroleum operation environment of -50 DEG C.