The present application discloses a data transmission method and apparatus. A specific implementation of the method includes: receiving to-be-transmitted data sent from an information sending end, and determining a sending coding type of the to-be-transmitted data; determining a receiving coding type of an information receiving end receiving the to-be-transmitted data; converting the to-be-transmitted data from the sending coding type to the receiving coding type using a preset transcoding model, to obtain transcoded transmission data, the transcoding model representing a corresponding relationship between the sending coding type and the receiving coding type; and sending the transcoded transmission data to the information receiving end. This implementation improves the data transmission efficiency.