A method for estimating a block error rate and a communication device are applied to the field of communications technologies. The method for estimating a block error rate includes: decoding N received coded code blocks to obtain multiple posterior probabilities APPs, where N is a natural number greater than 1; obtaining, according to the multiple posterior probabilities APPs and a preset policy, a result indicating that the decoding of each coded code block is correct or incorrect, where the preset policy includes: when a sum of absolute values of the multiple APPs is greater than or equal to a preset threshold, the decoding is correct; and obtaining a decoding block error rate according to a result indicating whether the decoding of the N coded code blocks is correct. In this way, the estimation of a decoding block error rate is implemented.