Legal analysis: generally called certificate mortgage, generally 300-500. You can return it when you leave the company. Companies with more formal procedures will give you a receipt when they join the company (you need to carry it with you, and you can make it up if you don't have it), but you won't be issued if it is rough. Generally, the personnel management and financial positions in my organization are responsible for refunding money. Go find them.
Legal basis: Article 9 of the Labor Contract Law of People's Republic of China (PRC), the employing unit shall not detain the employee's resident identity card and other documents, and shall not require the employee to provide guarantee or collect property from the employee in other names.