The invention discloses a three-in-one key burglarproof lock cylinder. The lock cylinder comprises a mechanical device. The mechanical device comprises a lock cylinder body, a lock liner, a drilling resistant steel strip, a hollow bead, an outer bottom bead, a dial wheel shaft, a lock cylinder shaft, a rectangular strip, a clamping bead, a billiard bead, a plug-pin strip, self-priming electromagnetic valves and a key. The three-in-one key burglarproof lock cylinder is reasonable in structure, convenient and practical, good in burglarproof property, durable in use, safe and reliable, easy to mount, low in construction cost and wide in using range. Closed parts are added in the lock cylinder, accordingly, the difficulty of opening the lock cylinder is increased, and the property is protected more effectively. The lock cylinder is suitable for houses and villas.