The invention relates to a 2D Log Gabor and composite coding method-based infrared iris authentication system and a method. The authentication system comprises an infrared iris image acquisition module used for acquiring a to-be-recognized iris image; an iris feature extraction module used for extracting iris two-dimensional texture features through a 2D Log Gabor filter; an iris feature vector encoding module used for encoding extracted feature vectors through a composite coding method; and an iris feature code matching module used for carrying out feature classification and recognition by using a projection extreme learning machine as a classifier. The authentication method comprises the following steps of acquiring a to-be-recognized iris image and preprocessing the image; extracting iris texture features; encoding the feature vectors of the extracted iris texture features; classifying the features by adopting a projection extreme learning machine as a classifier; calculating the hamming distance according to the classification result; and judging whether irises are from the same person or not according to the hamming distance. The system and the method are high in authentication precision.