The effect of different oxygen contents (21%, 24%, 27%, and 30%) and gas rate flows (27, 29, 31, 33, and 35 m(3)/h) on flame characteristics during the biodiesel combustion, such as flame length, area, brightness, and breakage degree, were studied using a homemade industrial furnace combustion system. The method consisted of keeping the fuel supply constant while increasing the flow of gas from 27 to 3S m(3)/h in 4 s in addition to cross tests with different oxygen contents (21%, 24%, 27%, and 30%) and gas rate flows (27, 29, 31, 33, and 35 m(3)/h). The results showed that oxygen-rich combustion gases have an enormous advantage in biodiesel combustion. As the gas flow rate increases, the flame length, flame brightness, and flame area gradually decrease but the flame breakage gradually increases. The flame can be stably burned under high gas flow rate: the gas supply amount is constant, as the oxygen concentration increases, the flame length and area increase, but the flame breakage decreases. As the gas supply increases, for an oxygen content of 21%, the length, area, brightness, and breakage degree of the flame fluctuated greatly, while under other oxygen-rich conditions, the flame could maintain a relatively stable combustion state. This research contributes to the industrialization of biodiesel.