The invention discloses a calling method of interstation distance dialing, which comprises the following steps: 1. distributing distant dialing operator selecting code PQR for each distant dialing operator in the whole net scale; 2. plugging PQR value in the called number as route selective number at interstation distant dialing calling; 3. extracting the PQR value through interstation distant switching equipment in the calling establishing course; providing interstation dialing cost check of PQR value through operator; making user select network freely; realizing selecting business for multi-operator.