In China, can the evidence obtained by criminal defense lawyers themselves not be presented to the judicial organs?

No need to submit it. The defense lawyer is not the third plaintiff. Different from the prosecutor of the first plaintiff and the victim of the second plaintiff, the main purpose of appearing in court is to safeguard the legitimate rights and interests of the defendant according to law and achieve a balance between prosecution and defense. Only responsible for providing evidence of innocence and guilt of criminal suspects and defendants.

People's Republic of China (PRC) Criminal Procedure Law 20 16

Article 35 A defender shall, according to facts and laws, put forward materials and opinions on the innocence, light crime or reduction or exemption of criminal responsibility of a criminal suspect or defendant, and safeguard the litigation rights and other legitimate rights and interests of the criminal suspect or defendant.

Article 46 A defense lawyer shall have the right to keep confidential the relevant information and materials of his client that he knows in his practice. However, if the defense lawyer knows that the client or others are preparing or committing criminal acts that endanger national security, public security and seriously endanger the personal safety of others, he shall promptly inform the judicial organs.