Abstract: The present invention relates to a detachable cylinder lock, which includes a case shell having an axial row of conic pin-holes for avoiding the pins falling out; a cylinder having a row of pinholes, in which a lower pin is located, corresponding to the pinholes of the case shell; the cylinder has an axial keyhole for a key inserting in, and a slant face (or a conic face) for the convenience of the cylinder inserting into the cylinder hole of the case shell; a follow block has a hole for the rear lug of the cylinder inserting in, and a cross hole penetrating through them for a fastening component screwing in or out.