Under normal circumstances, in criminal proceedings, if the defendant refuses to accept the judgment of first instance after it takes effect, he can appeal to a higher court. If the court of second instance changes the judgment of first instance and the judgment takes effect, then the trial procedure of criminal case is over and there is no need to return it to the court of first instance.
It should be noted that in criminal proceedings, the defendant can appeal to a higher court until the Supreme People's Court. Therefore, if the judgment of the court of second instance is appealed to a higher court, the trial procedure of the case is still not over, and further trial and judgment are needed.