An inter prediction method, including: when a prediction mode of a to-be-processed picture block is an affine motion model-based advanced motion vector prediction mode, obtaining control point motion vectors of the to-be-processed picture block, where the control point motion vectors meet preset first motion vector resolution and/or first motion vector bit depth; then, deriving a motion vector of each motion compensation unit in the to-be-processed picture block based on the control point motion vectors; and obtaining a reconstructed block of the to-be-processed picture block based on the motion vector of each motion compensation unit.