The invention discloses a method for determining the signal-to-noise ratio of an optical remote sensor by combining satellite orbit characteristics. During determination of the signal-to-noise ratio of the optical remote sensor, the characteristics of the flight orbit of a satellite and a ground object are taken into full consideration, and the capability of the optical remote sensor is developedto the greatest extent, so that the optical remote sensor can acquire enough energy during flight of the satellite on orbit, the imaging quality of a remote sensing satellite is greatly improved, andthe problem of dark images acquired by a high-resolution on-orbit remote sensor is solved.