It's effective. The official seal and signature on the labor contract must not be wrong. If the company name is wrong, you can negotiate with the company to change it.

Labor Contract Law

Article 16 A labor contract shall come into effect after the employer and the employee reach an agreement through consultation and sign or seal the text of the labor contract.

Article 35 The employer and the employee may change the contents agreed in the labor contract through consultation. Changes to the labor contract shall be made in written form.

The revised text of the labor contract shall be held by the employer and the employee respectively.