"远洋定期客轮" can be translated into English as "ocean-going regular passenger liner" or "transoceanic scheduled passenger ship".
"Ocean-going" or "transoceanic" emphasizes that the ship is capable of long-distance voyages across oceans.
"Regular" or "scheduled" indicates that the ship operates on a fixed, predetermined schedule.
"Passenger liner" or "passenger ship" clearly defines the type of vessel as one designed for carrying passengers.
Both translations convey the meaning accurately, and the choice between them may depend on the specific context or preferred terminology.