A search space blind detection method and a communication apparatus. The method includes: a terminal receives indication information that corresponds to a first search space set and that is sent by a network device, where the indication information is used to indicate one or more search space groups, one search space group includes at least two search spaces having an association relationship, and at least one search space in one search space group belongs to the first search space set; and then, the terminal determines, based on the indication information, a quantity of blind detection times corresponding to the first search space set. The quantity of blind detection times corresponding to the first search space set is determined by considering an association relationship between a plurality of search spaces.