A quick-assembly seat includes a seat body, a clamping assembly and a driving assembly. The clamping assembly includes a clamping member slidably connected to the seat body, and the clamping member includes a first driving surface. The driving assembly includes a driving member slidably connected to the seat body, and the driving member includes a second driving surface. The driving member is configured to slide relative to the seat body, such that the second driving surface presses against the first driving surface, and the driving member drives the clamping member to slide relative to the seat body to clamp or unclamp a quick-release part. The quick-release assembly includes the quick-assembly seat and the quick-release part that are connected. The quick-release part can be connected to a photographing device, and the seat body can be mounted on a bracket. The photographing device can be quickly assembled on the bracket and disassembled.