Legal analysis: Whether the property agreement after marriage is unfair or not depends on the specific circumstances. In general, the agreement is invalid under the following circumstances:

1. The civil subject is unqualified;

2. One party makes the other party act against its true meaning by means of fraud, coercion or taking advantage of others' danger;

3. Malicious collusion that harms the interests of the state, the collective or a third party;

4. Violating laws or social interests:

5. Covering up illegal purposes in a legal form.

Legal basis: Article 162 of the Civil Code of the People's Republic of China, the following property acquired by husband and wife during the marriage relationship is the common property of husband and wife, and belongs to both husband and wife: (1) salary, bonus and remuneration for labor services; (2) Income from production, operation and investment; (3) Income from intellectual property rights; (4) Inherited or donated property, except as provided for in Item 3 of Article 163 of this Law; (five) other property that should be owned by * * *. Husband and wife have equal rights to dispose of the same property.

Article 163 The following property is the personal property of one spouse: (1) the premarital property of one spouse; (2) Compensation or compensation obtained by one party for personal injury; (3) Property determined to belong to only one party in the will or gift contract; (4) Daily necessities used exclusively by one party; (5) Other property that should belong to one party.

article 164 the debts incurred by both husband and wife with the same signature or the subsequent ratification by one of them, as well as the debts incurred by one of them in his own name for the daily needs of the family during the marriage relationship, belong to the same debts of husband and wife. The debts incurred by one of the husband and wife during the marriage relationship in their own name beyond the daily needs of the family do not belong to the same debts of husband and wife; However, the creditor can prove that the debt is used for the husband and wife's * * * life, * * * production and operation, or based on the same meaning of both husband and wife.

Article 165 A man and a woman may agree that the property acquired during the marriage relationship and the property before marriage shall be owned by them, owned by them all or part of them, and owned by them part of them. The agreement shall be in writing. Where there is no agreement or the agreement is unclear, the provisions of Articles 162nd and 163rd of this Law shall apply. The agreement between husband and wife on the property obtained during the marriage relationship and the property before marriage is legally binding on both parties. The husband and wife agreed that the property acquired during the marriage relationship should be owned by each other, and if the other party knows the agreement, the personal property of the husband or wife should be used to pay off the debts owed by the husband or wife.

Article 166 During the marriage relationship, under any of the following circumstances, one of the spouses may request the people's court to divide the joint property: (1) one spouse has hidden, transferred, sold, damaged or squandered the joint property or forged the joint debt of the husband and wife, which seriously damages the interests of the husband and wife; (two) one party has the legal obligation to support people suffering from major diseases and need medical treatment, and the other party does not agree to pay the relevant medical expenses.