Example uplink control information transmission methods and apparatus are provided. One example method includes determining a quantity of resources for sending UCI by a terminal device based on first information. The first information includes scheduling information, a ratio of a quantity of bits of the UCI to a quantity of bits of data, a first preset parameter, a parameter β, a quantity of available resources of a PUSCH, and a parameter α. The terminal device sends the UCI to a network device based on the determined quantity of resources for sending the UCI.