Through a practical case, this paper explores the legal effectiveness of housing lease contracts and the protection of tenants' rights and interests. The landlord unilaterally breached the contract due to personal reasons, attempted to forcibly take back the house, and even illegally changed the lock or invaded the tenant's residence, infringing on the tenant's legitimate rights and interests. The police intervened in a timely manner, pointing out that the landlord's behavior was suspected of being illegal, and ultimately the landlord was administratively detained according to law. This case emphasizes the legal binding force of contracts and the importance of protecting tenants' rights in leasing relationships.