A pickproof lock has a hollow housing, a lock shaft and a sleeve mounted in the housing, multiple axial pin sets mounted in the lock shaft and the sleeve, and at least one radial pin set mounted in the housing and the lock shaft. When unlocking the pickproof lock, the key is able to push the axial pin sets and the at least one radial pin set to unlocking positions, so as to drive the lock shaft to rotate and to unlock the pickproof lock. The complexity of the pickproof lock is increased. People with bad intentions are unable to unlock the pickproof lock with a lock picking tool, such as a round tube. Accordingly, personal goods or private matters can be safely protected by the pickproof lock.