Considering security of the protocol and necessity of the controller for quantum communication, a novel controlled quantum secure direct communication protocol is proposed. In the protocol, the controller prepares and distributes channel particles and decides whether to communicate, and the information of the controller plays a great role in operation of the protocol. The security of the protocol and amount of information transmission are improved by using the encoding operation after encryption and introducing auxiliary particles. The information receiver performs unitary operation according to the processed message and obtains secret information by reverse decoding according to the agreed encryption rules. All published information is not directly related to secret information, thus avoiding the problem of information leakage. The analysis results show that the protocol can resist attacks from third parties and eavesdroppers, and its quantum communication efficiency is 28.75%.