The invention discloses a narrow overlap welding method of 460MPa-grade low-alloy high-strength steel. Welding is carried out according to the overlap amount, the compensation amount, the welding speed, the welding pressure, the welding temperature and the welding current acquired through formula computing of the method. According to the narrow overlap welding method of the 460MPa-grade low-alloyhigh-strength steel, because of the computational formula welding parameter determination manner, the disadvantage that welding parameters are set by adopting manual experience is avoided, the disadvantage that weld joint quality cannot be scientifically measured because weld joint heat cannot be measured on line is avoided, the overlap welding quality is controlled scientifically and reasonably,and the stability of welding quality is improved. By adopting the narrow overlap welding method of the 460MPa-grade low-alloy high-strength steel, it is achieved that narrow overlap welding meets therequirements of a production technology by one time of welding, the phenomenon that in the continuous annealing production process, stop or speed reduction appears because of welding is avoided, and it is guaranteed that the product quality of a continuous annealing production line is stable.