The invention relates to a parallel type support system capable of achieving on-orbit optical load replacing and belongs to the technical field of aerospace. The system comprises a load mounting platform, a pair of guide rails, a load operation handle, a first support point, a first locking point, a second support column, a second locking point, a third support point and a third locking point, wherein each support point comprises a platform side structure and a load side structure, each locking point comprises a platform side structure and a load side structure, the load side structure of eachsupport point is integrated with the load side structure of the corresponding locking point, and the platform side structure of each support point and the platform side structure of the correspondinglocking point are coaxially mounted. The parallel type support system has the advantages that by using the parallel support manner using the kinematics support structure and the locking point structure, the support problem of on-orbit spatial optical load replacing is solved; the support interface structure of the parallel type support system is convenient to assemble, capable of saving space, high in heat and force environment adaptability, good in operability and the like.