Timing advance updating method, terminal device, chip system and medium

The invention provides a timing advance updating method, terminal equipment, a chip system and a medium, which are applied to the field of satellite communication, and the terminal equipment automatically updates the timing advance, so that the updating efficiency of the timing advance can be improved, and the signaling overhead can be reduced. The method comprises: a terminal device determining a time deviation, and then determining a second timing advance according to the time deviation and a first timing advance; wherein the time deviation is a deviation value of an initial position of a first downlink channel in a time domain relative to an initial position of a second downlink channel in the time domain, and the first downlink channel is a downlink receiving channel of the terminal equipment at the current moment; the second downlink channel is a downlink receiving channel of the terminal device when the terminal device and the satellite base station complete uplink and downlink synchronization through t