The invention discloses an all-fiber endoscopic OCT probe based on a tapered structure, which comprises an optical component formed by welding multiple sections of fibers, a transmission component and a protective sleeve. The optical component has two structures, wherein one structure is composed of a transmission single-mode fiber, a transition section tapered fiber and a large-core multi-mode fiber, and the other structure is composed of a transmission single-mode fiber and an asymmetric double-tapered fiber. Each tapered fiber is formed by tapering the large-core multi-mode fiber, and mode field diameters at the welding parts of all sections of fibers of the optical component are consistent. The endoscopic OCT probe disclosed by the invention has no need of an optical focusing lens, is compact in structure, high in transmission efficiency and large in range of focal depth, and is very suitable for high-quality OCT imaging of the heart and cerebral vessels.