A novel bandwidth current operational amplifier was presented to meet the demand of video signal processing for a pipelined Analog-to-Digital Converter(ADC) with large dynamic ranges and higher operation speeds. In the system, the main amplifier adopts a cascode structure and the auxiliary amplifier is a current mode amplifier. In order to improve circuit speeds and to decrease parasitic capacitance, the input signal was applied to the source terminal. A current-mode feedback circuit was utilized to stabilize the out common mode voltage through adjusting the currents of the main amplifier and the amplifier was implemented in TSMC 0.18 μm CMOS process with a consumer of 9.3 mW. Experiment results show that the circuit has an open loop gain of 83.19dB, a unity gain bandwidth of 1.6 GHz and a phase margin of 61.6°. A pipelined ADC for high-resolution video signal process using this current amplifier achieves a resolution of 10 bit and a sampling rate of 170 MS/s. Compared with traditional amplifiers , the proposed amplifier shows a lower power dissipation and higher response speeds and satisfies the requirements of the video signal processing.