1. First of all, we should negotiate and sue with the landlord. As for the deposit, it is generally stipulated in the contract, and the landlord's behavior is a breach of the contract, which can be handled in the way agreed in the contract; However, in real life, this kind of negotiation can not solve the problem generally, and most of them will go to the stage of prosecution. A lawsuit to the court can not only require the return of the deposit, but also require them to pay liquidated damages according to the contract.
 2. However, when prosecuting, we must prepare sufficient evidence, especially to prove some matters, for example, there is a lease relationship and the lease relationship has ended. Without the above matters that need to compensate the landlord, the landlord does have the act of seizing evidence. In order to prove the facts, we usually keep the information related to renting as evidence to support the claim.
 Legal basis
 Article 119 of the Civil Code of the People's Republic of China [Binding force of contract] A legally formed contract is legally binding on the parties.