A method for determining a physical sidelink feedback channel resource and an apparatus are provided. The method includes: a first terminal device sends multicast information to at least two second terminal devices. The first terminal device determines, based on a total quantity of terminal devices in a multicast group and a resource group of physical sidelink feedback channel resources, a physical sidelink feedback channel resource corresponding to each second terminal device. The first terminal device receives, based on the physical sidelink feedback channel resource corresponding to each second terminal device, feedback information sent by each of the at least two second terminal devices. According to the foregoing method, physical sidelink feedback channel resources can be allocated to the terminal devices in the multicast group.