The invention provides an expanding pulling-out device in a diesel engine cylinder sleeve. The expanding pulling-out device comprises a conical face drawing rod, a supporting beam, an adjusting casing pipe and multiple expansion blocks. The outer side of the conical face drawing rod is sequentially sleeved and connected with the expansion blocks, the adjusting casing pipe, a first adjusting nut, the supporting beam and a second adjusting nut from bottom to top. The expansion blocks, the adjusting casing pipe, the first adjusting nut, the supporting beam and the second adjusting nut are sequentially connected in a contact manner from bottom to top. According to the expanding pulling-out device in the diesel engine cylinder sleeve, the expansion blocks slide downwards through opening grooves to expand the cylinder sleeve, the cylinder sleeve is lifted upwards through the conical face drawing rod, and the expansion blocks can be attached to the inner wall face of the cylinder sleeve more tightly. The opening grooves are evenly formed in the axial direction of a conical guide face, the attaching stress between the expansion blocks and the cylinder wall is more even, the acting area is enlarged, demounting of the cylinder sleeve is facilitated, and cylinder sleeve inner surface scratches caused by sliding of the expansion blocks are effectively avoided; and meanwhile the problem that the cylinder sleeve with a connecting rod and a piston is hard to demount is solved.