The biometric authentication technique based on the pattern of a personal iris is to be applied to any access control system requiring a high level of security due to its simple algorithms,fast recognition and low rate of false recognition.The Daugman algorithms used to recognize iris are improved in the following two aspects:1) The iris is located by the combination of Gradient-Decomposed Hough Transform with Integro-Differential Operators:and 2) Characteristics of iris images can be collected by means of a multi-channel gabor filter,which have effectively solved the problem of a bright point effect aroused from non-scattered man-made light in the Daugman algorithms and thus enhanced the usefulness and adaptability of iris recognition.