Legal analysis: Training institutions and trainees need to sign a contract, and the contract signed by both parties through consultation is valid.

Legal basis: Article 143 of the Civil Law of People's Republic of China (PRC) is valid for civil juristic acts that meet the following conditions: (1) The actor has corresponding capacity for civil conduct; (2) the meaning is true; (three) does not violate the mandatory provisions of laws and administrative regulations, and does not violate public order and good customs.