The invention discloses a manifold pre-integration-based visual inertial milemeter posture estimation method and device. After finishing the initialization of the visual inertial milemeter system, themethod comprises: visual inertial data alignment, visual optical flow position posture calculation, inertial pre-integration, visual and inertial joint optimization, window marginalization and aboveprocess repetition so that continuous estimation of camera postures is realized. Compared with the single visual milemeter system, the manifold pre-integration-based visual inertial milemeter system has a higher positioning precision, effectively utilizes inertial information in the milemeter system based on the manifold pre-integration algorithm, inhibits noise propagation of the system and reduces the influence of the inertial zero drift on the positioning accuracy of the milemeter.