Disclosed is a suspension device comprising an upper connecting member and a lower bearing member. The upper connecting member comprises a first upper jointing portion and a second upper jointing portion, and the lower bearing member comprises a first lower jointing portion and a second lower jointing portion. The first upper jointing portion is provided with a first opening, the first lower jointing portion is substantially T-shaped. The root part of the first lower jointing portion can be rotated freely in the lower part of the first opening. The second upper jointing portion is provided with a second opening and a third opening that are elongated, the second lower jointing portion is provided with a first side plate and a second side plate configured to be inserted into the second opening and the third opening, respectively.