A method includes: determining, by a first terminal device, a first timing of a first measurement signal used by a second terminal device for measurement, where a first network device serving the first terminal device is different from a network device serving the second terminal device; determining, by the first terminal device, a second timing of a second measurement signal used by the first network device for measurement; and sending, by the first terminal device, the first measurement signal and the second measurement signal based on the first timing and the second timing respectively.