The present invention relates to an annular scanning device for optical tomography scanning and imaging system, which comprises a carrying base, a rotating member, a plurality of optical channel modules, and a driving module. The rotating member is disposed on the carrying base. The plurality of optical channel modules are disposed annularly on the rotating member and connected to the rotating member. When the driving module drives the rotating member to rotate, a plurality of optical channel assemblies of the plurality of optical channel modules move towards or away from the center of the rotating member for adjusting the distance between the plurality of optical channel assemblies and an object under test.