An uplink control channel transmission method, a terminal device and a network device are provided. The terminal device determines, according to the maximum code rate at which an uplink control channel is transmitted, uplink control information carried in the uplink control channel; and optimization can be performed according to different uplink control information to ensure reliable transmission of the uplink control information. The method comprises: the terminal device determines, from the maximum code rate of at least one uplink control channel, the maximum code rate at which the uplink control channel is transmitted; and the terminal device determines, according to the maximum code rate at which the uplink control channel is transmitted, uplink control information carried in the uplink control channel.