The invention relates to a face identification based living body detection method and apparatus. The method comprises the steps of: carrying out identity authentication on a to-be-detected user in a to-be-detected crowd through face identification; obtaining a training eye image of the to-be-detected user watching a training sight point, and further extracting training sightline features; obtaining a to-be-detected eye image of the to-be-detected user watching a system random point, and further extracting to-be-detected sightline features; for the to-be-detected user passing the identity authentication, carrying out primary sight point position estimation by adopting an adaptive linear regression algorithm by utilizing a training sight point sequence, the training sightline features and the to-be-detected sightline features; adding the system random point, meeting the predetermined conditions, in the sight point position obtained by primary sight point position estimation into the training sight point sequence to form a new sight point sequence, and carrying out incremental sight point position estimation; and estimating the estimated sight point position according to the incremental sight point position, and carrying out living body judgment by utilizing KL divergence.