In order to meet the need of high spatial resolution and high count rate in the imaging of far ultraviolet band, the method of acquiring the induced charge of the photon count imaging detector is described, which can be used in the imaging spectrometer for remote sensing of far ultraviolet band in the ionosphere of the earth. The relation between the parameters of the charge sensitive amplifier with pulse shaper is studied. The influence of the rise time of the charge sensitive amplifier and the time constant of the pulse shaper on the noise and counting rate is analyzed by numerical model. The selection principle of network parameters is proposed, and a front-end readout circuitry for photon count imaging detector based on wedge and strip anode is developed with discrete electronic components suitable for space applications. The experiment results show that when the shaping time is 500 ns, the equivalent input noise charge of readout circuits is about 230 e, and the rise time of the charge sensitive amplifier is better than 8 ns, which have better consistency with the calculated values. The spatial resolution of the measured images is up to 7.13 lp/mm, and the highest counting rate is 86.2 kcps, which meets the requirements of the far-ultraviolet band imaging spectrometer on-orbit mission operations.