[en] The control system of the pellet injector is introduced in detail and the system mainly includes two parts: the present and the remote control system. The present control system controls the injector and provides the interface to the remote system. And the remote control system has a acquired present signals with analog input card and perform the actions through digit output card, it also has an interface for Windows programming easily used by the operator: when carrying out the pellet injection experiments. Through several HT-7 campaigns, the remote control system has been validated to be feasible and reliable and has made successful shots for studying the interactions between the pellets and plasma