Legal analysis: According to prison regulations, prisoners should be cut short, and the length of female prisoners to their ears is basically bald for male prisoners. Therefore, as long as you are in prison, your hair must meet the requirements. Before you were sent to prison, your hair was too long. You should deal with it immediately after you go in.
Legal basis: Article 10 of the Code of Conduct for Criminals in People's Republic of China (PRC) shall maintain personal hygiene, take a bath, have a haircut, shave and cut nails on time, and change clothes and bedding regularly.