The invention aims at providing an oil burning boiler igniter with a preheating device. The oil burning boiler igniter is good in ignition effect. The oil burning boiler igniter with the preheating device comprises an ignition plug and a power source excitation device which is connected with the ignition plug through a cable and an ignition switch. The oil burning boiler igniter is characterized by further comprising a preheating cavity with a heating unit inside, and the preheating cavity is provided with an oil inlet and an oil outlet; and the ignition plug is fixed to the oil outlet. When the igniter is mounted, the oil inlet of the preheating cavity is connected with a heavy oil pipeline of a boiler to form a branch path. In the ignition process, firstly, the heating unit is utilized for preheating heavy oil in the preheating cavity, and when the heavy oil rises to the temperature suitable for ignition, the ignition plug is utilized for igniting the heavy oil sprayed out of the oil outlet, so that the condition that due to the external low-temperature environment, the heavy oil is hard to ignite can be avoided.