This dynamic image processing device (20) for a head mounted display includes an attitude detection means (30) capable of detecting the attitude of an imaging device affixed to the head of a user, a first image deviation amount calculation means (41) that calculates a first image deviation amount (G1) in the yawing and pitching directions of the imaging device based on the detection result of the attitude detection means, a second image deviation amount calculation means (42) that calculates a second image deviation amount (G2) between a past image (52) and a current frame image (51) based on the first image deviation amount, the current frame image captured by the imaging device, and the past image, and an image synthesis means (43) that corrects the past image based on the second image deviation amount and synthesizes the past image and the current frame image.