The present disclosure provides a handover method for grant-free transmission, a terminal device, and a network device. The handover method includes: sending, by a first network device, a handover request message to a second network device to request to hand over a terminal device from the first network device to the second network device to perform grant-free transmission; receiving, by the first network device, a handover request acknowledgement message sent by the second network device to acknowledge handing over the terminal device from the first network device to the second network device to perform grant-free transmission; and sending, by the first network device, a handover instruction message to the terminal device to instruct the terminal device to transmit a signal to the second network device on a CTU resource in a grant-free transmission mode.