The invention relates to flexible fixture equipment for assembling of a large-size thin-wall cylindrical component in the automatic assembling field. The flexible fixture equipment comprises an internal supporting fixture array which is arranged inside the thin-wall cylindrical component and is used for supporting, an external pressing fixture array which is arranged outside the thin-wall cylindrical component and is used for pressing, and a supporting structure thereof, wherein the supporting structure is fixedly arranged on the ground and is connected with the external pressing fixture array to realize vertical adjustment, the external pressing fixture array uniformly applies pressing force to the thin-wall cylindrical component along the circumferential direction from outside to inside, the internal supporting fixture array uniformly provides supporting force to the thin-wall cylindrical component along the circumferential direction from inside to outside, and the uniform clamping and fixing of the large-size thin-wall cylindrical component are realized through the matching of the pressing force and the supporting force. The flexible fixture equipment has the advantages of compact configuration, multipoint adjustment, uniform stress, small deformation, high assembling efficiency and strong bearing capacity.