The invention provides a bar production line steel bar splitting automatic steel bar counting device. The automatic steel bar counting device comprises a first output pulse generation unit, a second output pulse generation unit, a first narrow pulse filter unit, a second narrow pulse filter unit and a counting processing unit. Counting pulses generated by the first output pulse generation unit and the second output pulse generation unit are subjected to narrow pulse interference filtering through the first narrow pulse filter unit and the second narrow pulse filter unit respectively, and are then, sent to the counting processing unit for counting; and the counting processing unit takes a larger count value as the bar counting result of the device. The automatic steel bar counting device also comprises a first transmission speed transformation unit and a second transmission speed transformation unit. The maximum width of the narrow pulse needing to be filtered can be changed adaptively with the transmission speed of bar products, and can be adjusted by changing circuit parameters. The device can be applied to occasions, where the number of the products needs to be counted, on various bar production lines for steel bar splitting and bar counting and the like.