The invention provides a space-based large-
diameter multi-constrained extrasolar terrestrial
planet detector structure. The structure comprises a platform
service module, a platform propelling module, a
payload, a
star sensor and a platform bottom plate; the back light path part of the
payload is embedded into the platform
service module, the
star sensor is installed on a high-rigidity back plate of the
payload, therefore, the attitude measuring error is decreased, and the
attitude control precision of a whole
detector is improved; intra-
detector subsystem single units of the detector are arranged on the obverse side of the platform bottom plate, and thrusters and air cylinders are arranged on the reverse side of the platform bottom plate. According to the space-based large-
diameter multi-constrained extrasolar terrestrial
planet detector structure, by means of
integrated design of a load platform, the
mass center of the whole detector can be lowered, and the enveloping limiting requirement of a
launch vehicle fairing can be met; meanwhile, attitude sensitive devices such as the
star sensor are arranged on the high-rigidity back plate of the payload, therefore, the attitude measuring error can be decreased, and the
attitude control precision of the whole detector can be improved. The structure can be effectively applied to
layout design of a similar detector structure with a large-
diameter multi-constrained space camera.