Theft -proof cylinder lock

The utility model relates to a theft -proof cylinder lock, it includes casing, spring lock, turning arm, and the lock core end of spring lock is equipped with siamesed first polygon axle, and the turning arm is equipped with second polygon axle, still include the slip cap, slip cap one end is equipped with the polygon trepanning that matees with first polygon axle, second polygon axle, and sets upbetween slip cap this end and the casing and be used for the spring that restores to the throne, and the slip cap other end slides and cup joints the lock core, and the lock core lateral wall is equipped with and switches on key hole and outside slide groove hole, forms through the pin between slip cap and the slide groove hole and slides spacingly, and just pinning, it is downthehole to stretchinto the key, when the key of lock core is downthehole when inserting the exact key, the key promotes the pin and drives slip cap endwise slip to being connected with first polygon axle, the transmission simultaneously of seco