A system and method for limiting access requests. In one system, a load balancer receives an access request, parses the access request into a UDP message, and transmits the UDP message to an aggregator; the aggregator accumulates the UDP message according to a predefined combination of data fields and a predefined duration so as to produce statistical data, and sends the statistical data to a summarizer in response to a request from the summarizer; the summarizer requests the statistical data from the aggregator according to a predefined request time interval, receives the statistical data from the aggregator, generates a blacklist for the access requests according to the received statistical data and a predefined rule, and sends the blacklist to the load balancer in response to a request from the load balancer. The load balancer determines a processing action on each of the received access requests according to the current blacklist.