The influence of micro-channel ratio of length to width and radius of curvature on imaging of lobster-eye optical system under the same parallel monochromatic light source condition was investigated. The results show that with the increase of the micro-channel ratio of length to width, the angular resolution becomes better while the total intensity of image surface decreases gradually. When the ratio reaches 25∶1, the effective area of focused X-rays reaches the maximum value. Under same micro-channel size condition, the change of radius of curvature has less influence on angular resolution, and the larger radius brings the larger effective area, but requires larger element volume for same field of view at the same time.