The invention discloses a combined spring variable-diameter wheel carrier for a variable-diameter wheel. The wheel carrier consists of hubs and an elastic variable-diameter piece, wherein the elastic variable-diameter piece and the hubs are arranged by using heart-shaped springs. The combined spring variable-diameter wheel carrier is rotated at a certain angle relative to a hub A and a hub C through a hub B, and drives the elastic variable-diameter piece to rotate in the peripheral direction of the hub B at the same time to make the elastic variable-diameter piece opened or closed so as to make the wheel diameter of the variable-diameter wheel variable. The wheel carrier has a spring steel structure, completely avoids movable hinge connection, removes a rubbing pair, is not sealed and lubricated, makes the structure more compact and greatly improves reliability.