Abstract: A data transmission method and apparatus are provided. The data transmission method is applied to a computer system including at least two coprocessors, for example, including a first coprocessor and a second coprocessor. A shared memory is deployed between the first coprocessor and the second coprocessor, and is configured to store data generated when subtasks are separately executed. Further, the shared memory further stores a storage address of data generated when a subtask is executed, and a mapping relationship between each subtask and a coprocessor that executes the subtask. Therefore, a storage address of data to be read by the coprocessor may be found based on the mapping relationship, and the data may further be directly read from the shared memory without being copied by using a system bus. This improves efficiency of data transmission between the coprocessors.