A method for controlling the charging of packet data service is disclosed, which includes: monitoring a number of event triggers; and when one of the event triggers is met, a TPF requesting charging rules from a CRF. In this way, the timing that the TPF requests charging rules from the CRF becomes controllable, and redundant information caused by the unnecessary charging rule from the TPF becomes avoidable, which enables interaction between the TPF and the CRF more effective and the charging control of packet data service reasonable and perfect.