A type of focal plane-curtain shutter was designed for a small focal plane aerial camera whose CCD image was orthogonal and vetical distribution due to the prism splicing. By taking the cog belt as the shutter curtains and the appropriate strip-shaped slit on the curtain as exposure slit, the exposure time of the shutter was determined by the velocity of the shutter curtains. The simultaneous exposure of two pieces of CCDs was implemented by the orthogonal layout and synchrodriving of two shutter curtains. According to the feedback of an encoder, the velocity of shutter motor was controlled by a DSP.Therefore, the shutter curtain ran at a steady speed and offered the exposure uniformity of CCD. Experiment results demonstrate that the shutter has a higher movement stability and a long life span in the range of continuous stepless adjustment exposure time (1/300-1/1 000 s), and its exposure error is less than 10%. Furthermore,by changing the shutter curtain and the slit width, the exposure time range can be extended. Obtained result shows that the performance of this shutter fully satisfies the requirements of area CCD aerial cameras.