A modular mobile vehicle with an adjustable wheelbase has a ready-made vehicle body, at least one wheelbase actuator and a seat module mounted on the ready-made vehicle body. The ready-made vehicle body has at least one motor, at least one rear wheel, two horizontally mounted guiding tubes, a front wheel frame slidably mounted around the two guiding tubes, and at least one front wheel. The at least one wheelbase actuator is mounted on the ready-made vehicle body, is located between the two guiding tubes, and is extendably connected with the front wheel frame. The seat module is mounted on the ready-made vehicle body and has a seat body detachably mounted on the ready-made vehicle body.
