The invention provides a pipeline anti-disengaging connecting assembly which comprises a gland; the gland is provided with a penetrating hole, the inner side wall of the penetrating hole is provided with an inclined guide face, an anti-disengaging ring is arranged in the penetrating hole, and a plurality of adjusting blocks are arranged between the anti-disengaging ring and the gland; an inclined pushing surface is arranged on the outer side wall of a ring body; or the anti-disengaging ring comprises a plurality of anti-disengaging blocks, and each anti-disengaging block is provided with an inclined pushing surface; and the inclined guide face and an inclined push face incline in the same direction relative to the axis of the gland, the side, facing the gland, of each adjusting block is provided with an outer inclined face, and the side, facing the anti-disengaging ring, of each adjusting block is provided with an inner inclined face. According to the pipeline anti-disengaging connecting assembly, the adjusting blocks are arranged between the anti-disengaging ring and the gland, the pipeline anti-disengaging connecting assembly can be suitable for connection of pipelines with different diameters only by replacing the anti-disengaging ring and the adjusting blocks, the gland can be matched with the pipelines with different diameters, funds and warehouse space needed when the pipeline anti-disengaging connecting assembly is backed up are relatively small, and the pipeline maintenance cost can be reduced favourably.