The invention relates to a method for production of high-strength threaded steel bar through on-line quenching and tempering, and heating blackening coating processes. The method includes the following steps of: subjecting a thread steel bar to multistage induction quenching heating, controlling the temperature of a quenching preheating zone at 700-850DEG C and the temperature of a quenching heat preservation zone at 820-950DEG C, and keeping the speed of quenching heating at 0.2-0.5m / min, then carrying out a quenching treatment, performing cooling at a cooling speed of 50-100DEG C / s, controlling the temperature of the thread steel bar released out of a spray ring cooling device at 60-100DEG C, then performing multistage induction tempering heating at a proceeding speed of 0.2-0.5m / min, controlling the tempering temperature at 500-650DEG C, delivering the tempered threaded steel bar to a surface coating zone to conduct heating blackening antiseptic treatment, implementing online packaging, and finally conducting offline storage. The technological method realizes on-line quenching and tempering, and heating blackening production of high-strength threaded steel bars, and has the characteristics of small deformation of workpieces, high production efficiency, energy saving, environmental protection, and less pollution, etc.