An uplink control channel resource determining method, a terminal, and a network side device are provided. The terminal determines the number N of uplink control information bits to be transmitted; the terminal determines the number of first resources according to a target encoding rate and N; the terminal determines the number of resources actually used according to the number of the first resources and the number of pre-configured resources; and the terminal transmits the uplink control information by means of the number of resources actually used.