A modular toy robot system (10-1, 10-2) comprising N cube type unit robots (100-1 - 100-N), wherein N is an integer equal to or greater than 2, wherein any one of the N cube type unit robots (100-1 - 100-N) is configured to act as a central control terminal, the cube type unit robot acting as the central control terminal is configured to assign a different unique ID number (ID1 - ID4) to each of the N cube type unit robots (100-1 - 100-N), each of the N cube type unit robots (100-1 - 100-N) comprises: a housing having a cube shape; a step motor installed within the housing; and a control unit installed within the housing is configured to control the step motor, a mounting groove on which a rotating body (300-1, 300-2) rotated by a rotation shaft of the step motor is mounted is formed in one side of the housing; a connection groove (141 - 145) formed on each of the remaining sides of the housing; wherein the connection grooves (141 - 145) have the same shape; each cube type unit robot is connected to another cube type unit robot through a connection body mounted on any of the connection grooves (141 - 145); and each control unit is configured to perform a step motor control sequence (1000-1 - 1000-4) corresponding to the unique ID number (ID1 - ID4) of the cube type unit robot among predefined N step motor control sequences (1000-1 - 1000-N), wherein N unique ID numbers transmitted to the respective N cube type unit robots (100-1 - 100-N) and the predefined N step motor control sequences (1000-1 - 1000-4) correspond to each other in a one-to-one manner; characterised in that each of the N cube type unit robots (100-1 - 100-N) further comprises a recognition device capable of recognizing information stored in a given recording medium; and when the recording medium is recognized by any one of the recognition devices included in the N cube type unit robots (100-1 - 100-N), the cube type unit robot comprising the corresponding recognition device is configured to act as the central control terminal. wherein any one of the N cube type unit robots (100-1 - 100-N) is configured to act as a central control terminal, the cube type unit robot acting as the central control terminal is configured to assign a different unique ID number (ID1 - ID4) to each of the N cube type unit robots (100-1 - 100-N), each of the N cube type unit robots (100-1 - 100-N) comprises: a housing having a cube shape; a step motor installed within the housing; and a control unit installed within the housing is configured to control the step motor, a mounting groove on which a rotating body (300-1, 300-2) rotated by a rotation shaft of the step motor is mounted is formed in one side of the housing; a connection groove (141 - 145) formed on each of the remaining sides of the housing; wherein the connection grooves (141 - 145) have the same shape; each cube type unit robot is connected to another cube type unit robot through a connection body mounted on any of the connection grooves (141 - 145); and each control unit is configured to perform a step motor control sequence (1000-1 - 1000-4) corresponding to the unique ID number (ID1 - ID4) of the cube type unit robot among predefined N step motor control sequences (1000-1 - 1000-N), wherein N unique ID numbers transmitted to the respective N cube type unit robots (100-1 - 100-N) and the predefined N step motor control sequences (1000-1 - 1000-4) correspond to each other in a one-to-one manner; characterised in that each of the N cube type unit robots (100-1 - 100-N) further comprises a recognition device capable of recognizing information stored in a given recording medium; and when the recording medium is recognized by any one of the recognition devices included in the N cube type unit robots (100-1 - 100-N), the cube type unit robot comprising the corresponding recognition device is configured to act as the central control terminal. a housing having a cube shape; a step motor installed within the housing; and a control unit installed within the housing is configured to control the step motor, a mounting groove on which a rotating body (300-1, 300-2) rotated by a rotation shaft of the step motor is mounted is formed in one side of the housing; a connection groove (141 - 145) formed on each of the remaining sides of the housing; wherein the connection grooves (141 - 145) have the same shape; each cube type unit robot is connected to another cube type unit robot through a connection body mounted on any of the connection grooves (141 - 145); and each control unit is configured to perform a step motor control sequence (1000-1 - 1000-4) corresponding to the unique ID number (ID1 - ID4) of the cube type unit robot among predefined N step motor control sequences (1000-1 - 1000-N), wherein N unique ID numbers transmitted to the respective N cube type unit robots (100-1 - 100-N) and the predefined N step motor control sequences (1000-1 - 1000-4) correspond to each other in a one-to-one manner; characterised in that each of the N cube type unit robots (100-1 - 100-N) further comprises a recognition device capable of recognizing information stored in a given recording medium; and when the recording medium is recognized by any one of the recognition devices included in the N cube type unit robots (100-1 - 100-N), the cube type unit robot comprising the corresponding recognition device is configured to act as the central control terminal.