I have signed the contract, but the other party won't give me a copy. Is it illegal?

If the contract is agreed that the contract can only be awarded after the "full payment", the other party's behavior is not illegal, but if it is a major misunderstanding, obviously unfair's contract can apply to the court to terminate the contract.

According to the Contract Law of People's Republic of China (PRC)

Chapter III Validity of Contract

Article 44 A legally established contract shall come into force upon its establishment.

Where laws and administrative regulations stipulate that examination and approval, registration and other procedures shall be handled, such provisions shall prevail.

Article 45 The parties may stipulate that the validity of a contract is subject to conditions. A contract with effective conditions shall take effect when the conditions are met. A contract with termination conditions is invalid when the conditions are met.

Article 52 A contract is invalid under any of the following circumstances:

(1) One party enters into a contract by means of fraud or coercion, which harms the interests of the state;

(2) Malicious collusion that harms the interests of the state, the collective or a third party;

(3) Covering up illegal purposes in a legal form;

(4) damaging the public interest;

(5) Violating the mandatory provisions of laws and administrative regulations.

Article 54 One party has the right to request a people's court or an arbitration institution to modify or terminate the following contracts:

(1) Due to a major misunderstanding;

(2) obviously unfair at the time of conclusion of the contract.

If one party leads the other party to conclude a contract against its true meaning by fraud, coercion or taking advantage of others' danger, the injured party has the right to request the people's court or arbitration institution to modify or cancel it.

The people's court or arbitration institution shall not revoke the request of the parties.

Extended data

The contents of the contract shall be agreed by the parties, and generally include the following clauses:

(1) The name and domicile of the party concerned;

(2) Subject matter;

(3) quantity;

(4) quality;

(5) Price or remuneration;

(6) Time limit, place and method of performance;

(7) Liability for breach of contract;

(8) Methods for resolving disputes.

Reference source

China People's Congress Network-People's Republic of China (PRC) Contract Law