Embodiments of this application provide a control information sending method and apparatus, where the method includes: obtaining a control information indication message from a first standard network, selecting a second standard network from one or more other networks that constitute a heterogeneous network with the first standard network, and sending the control information indication message to the second standard network, and then to a client over the second standard network. The control information indication message is used to instruct to substitutively send control information of the first standard network. According to the method and apparatus provided, the control information of the first standard network is substitutively sent over the second standard network, and sending the control information does not need to occupy bandwidth of the first standard network. Therefore, in comparison with the prior art, a network capacity of service data sent over the first standard network can be increased.