A multi-car elevator system (1, 1A) for controlling a multi-car elevator in which a plurality of cars (11A-G) move in the same moving path, comprising: a call input display unit that is provided in a platform hall where the car (11A-G) stops and receives a destination from a passenger; a group management control unit that receives destination information, which is transmitted from the call input display unit, regarding the destination of the passenger, and assigns the passenger to a specific boarding group (21A-C) from among a plurality of boarding groups (21A-C) based on the destination information; and a car control unit that controls moving of the car (11A-G) and transmits movement information regarding the moving of the car (11A-G) to the group management control unit, wherein the group management control unit calculates boarding guidance information, which is information regarding the car (11A-G) to be boarded by the passenger, for each of the plurality of boarding groups (21A-C) based on the movement information received from the car control unit, and outputs the boarding guidance information to an outside, wherein the platform hall is provided with a plurality of platforms (51A-B) where the car (11A-G) stops, and wherein the boarding guidance information output by the group management control unit also includes information regarding a platform (51A-B) where the car (11A-G) to be boarded stops among the plurality of platforms (51A-B), characterized in that, the platform hall is provided with a plurality of waiting position display units (104A-C), where the passenger stands by, for each of the plurality of boarding groups (21A-C), wherein the multi-car elevator system (1, 1A) further comprises a boarding allocation availability determination unit that determines whether to board from the platform (51A-B) based on moving lines of movement from the plurality of waiting position display units (104A-C) to the plurality of platforms (51A-B), and wherein the group management control unit calculates the boarding guidance information based on information determined by the boarding allocation availability determination unit. a call input display unit that is provided in a platform hall where the car (11A-G) stops and receives a destination from a passenger; a group management control unit that receives destination information, which is transmitted from the call input display unit, regarding the destination of the passenger, and assigns the passenger to a specific boarding group (21A-C) from among a plurality of boarding groups (21A-C) based on the destination information; and a car control unit that controls moving of the car (11A-G) and transmits movement information regarding the moving of the car (11A-G) to the group management control unit, wherein the group management control unit calculates boarding guidance information, which is information regarding the car (11A-G) to be boarded by the passenger, for each of the plurality of boarding groups (21A-C) based on the movement information received from the car control unit, and outputs the boarding guidance information to an outside, wherein the platform hall is provided with a plurality of platforms (51A-B) where the car (11A-G) stops, and wherein the boarding guidance information output by the group management control unit also includes information regarding a platform (51A-B) where the car (11A-G) to be boarded stops among the plurality of platforms (51A-B), characterized in that, the platform hall is provided with a plurality of waiting position display units (104A-C), where the passenger stands by, for each of the plurality of boarding groups (21A-C), wherein the multi-car elevator system (1, 1A) further comprises a boarding allocation availability determination unit that determines whether to board from the platform (51A-B) based on moving lines of movement from the plurality of waiting position display units (104A-C) to the plurality of platforms (51A-B), and wherein the group management control unit calculates the boarding guidance information based on information determined by the boarding allocation availability determination unit.