For the rapid development of space remote sensing technology and the improvement of demand for space detection precision, this paper researches the more feasible and effective technological routes for ultra large aperture optical remote sensors. Several kinds of optical remote sensors that have been launched or planed are included, such as monolithic aperture imaging system, deployable segmented imaging system, interferometric synthetic aperture imaging system and diffractive imaging system. The research process, structure characteristics, developing states and application fields of the remote sensors are described. Details on the performance characteristics and application situations of various sensors are discussed in later sections. According to the requirements of space optical remote sensors with high resolution and high imaging quality, some suggestions on developing space optical remote sensors with ultra large apertures of 2—4 m, 4—10 m and some super large apertures are put forward respectively based on the current technical conditions and development trends.