A HRPD network access authentication method based on CAVE algorithm is provided. An AT (Access Terminal) generates a random number “RAND” necessary for a calculation of an AUTH1 by using a “Random text” included in the CHAP Challenge message. A UIM (User Identity Module) card works out the AUTH1 by using the random number “RAND” and an SSD_A (Shared Secret Data A) in the UIM card. The AT carries the AUTH1 in a Result field of the CHAP Response message. An AN-AAA (Access Network-Authentication, Authorization, and Accounting) generates the random number “RAND” necessary for the calculation of an AUTH2 by using a “Random text” included in a Radius Access Request message. The AN-AAA works out the AUTH2 by using the random number “RAND”. The two results AUTH1 and AUTH2 are compared. If the results are the same, the authentication on the AT passes. Otherwise, AT access is rejected.