To provide a fuel injection control device capable of adjusting a pressure feed amount of a high pressure pump to a target pressure feed amount with high accuracy, and a fuel injection system using the same.

The fuel injection control device samples driving current of a feed pump at a prescribed time interval, executing AD conversion of the same, and subjects the same to a band-pass filter (S400, S402), determines a rising start angle TG when the driving current falls within a prescribed range to start rising after passing through the filter (S404), and determines a rising end angle TR when the driving current falls within a prescribed range to terminate the rising (S406). An estimated pressure feed amount of the high pressure pump is determined on the basis of the rising start angle TG and the rising end angle TR (S408), an adjustment valve is controlled on the basis of a common rail pressure (S412), when a rail pressure sensor is normal (S410:Yes), and the adjustment valve is controlled on the basis of the estimated pressure feed amount (S414), when the rail pressure sensor is abnormal (S410:No).