Is it unsafe to connect rooms in a hotel?

No. Relatively safe, there are locks on both sides, just don't forget to lock. This kind of room has advantages and disadvantages. The advantage is that if you are traveling for the whole family, you can book this kind of room with the hotel in advance and let the hotel give you the key to this room, so that the family will be very convenient, which is equivalent to living in a two-bedroom suite. And the room rate will be more cost-effective than the two-bedroom suite of the same level hotel. The disadvantage is that the sound insulation effect is too poor. When you sleep at night, you can clearly hear the voice of the tenant next door. A connecting room refers to a room where two rooms are connected by a door.