Access control method for physical random access channel

The invention provides an access control method for a physical random access channel (PRACH). The method comprises the steps that cluster classification is carried out on users according to quality of service (QOS) of terminal request service, an evolved Node B (eNB) distributes the number of at most M permissible clusters; wherein each cluster has the maximum time delay requirement, when user quantity is increased to a certain number, the user time delay of a cluster exceeds the maximum transmission time delay, the access attempt time for the cluster of the least priority is prolonged, when the access attempt time of the cluster is longer than the time spent in starting dynamic access baring (DAB) by a system, the DAB is started; and when the eNB detects that the quantity of successfully received msg1 is greater than a threshold value, the cluster of maximum QOS in a DAB set is prohibited starting. While taking the QOS of the user into account, the method realizes dynamic control on access, increases the access success rate of the users, provides differentiated services for the users, and improves the economic benefits of the system.