We designed and modeled a short-magnetic-focusing pulse-dilation framing camera. Based on the principle of pulse dilation and the equation of photoelectron motion, we studied the fs-photoelectron acceleration, transmission, and imaging characteristics in a pulse-dilation system. In addition, we analyzed the temporal-spatial dispersion and discussed the methods for its reduction. The simulated results show that when the pulse-dilation system has a length of 500 mm, a gradient of dilation pulse of 10 V·ps -1, and an accelerating field of 2 kV·mm -1, the total physical-temporal resolution resulting from temporal dispersion is 1.62 ps, which is 70% of the temporal resolution of the camera. The spatial dispersion is 62.87 μm, and the image contrast is reduced by 13.58%. Thus, the influence of temporal-spatial dispersion on physical-temporal resolution and imaging contrast can be effectively reduced by enhancing the accelerating field.