A method for determining a slot format and a device are disclosed, to determine an ECP slot format. The method for determining a slot format includes: obtaining first indication information, where the first indication information includes indication information of a slot format a, the slot format a is one of slot formats of a first-type slot, the first-type slot includes N symbols, and N is 14; and determining a slot format b of 2(μ-μa) consecutive second-type slots based on a subcarrier spacing μa applicable to the first indication information, a subcarrier spacing μ applicable to the second-type slot, and the indication information of the slot format a, where the second-type slot includes M symbols, and N is not equal to M.