The invention discloses a steering control system of a mini cable-free swimming robot. The steering control system comprises side fins positioned on two sides of a robot body and in hinged connectionwith the robot body, a piezoelectric ceramic pile driving the side fins, mini pressure sensors positioned on the side fins, mini photoelectric encoders positioned at positions where the side fins arehinged to the robot body, a single chip microcomputer controller and an inside radio frequency transceiver, and further comprises an external radio frequency transceiver, a single chip microcomputer main controller and a track recorder which are outside the robot body independently the single chip microcomputer controller and the inside radio frequency transceiver are positioned inside the robot body, the single chip microcomputer controller, the inside radio frequency transceiver, a driving power source and the piezoelectric ceramic pile are sequentially connected through leads, the single chip microcomputer controller is connected with the mini pressure sensors and the photoelectric encoders through leads, the outside radio frequency transceiver, the single chip microcomputer main controller and the track recorder are sequentially connected through leads, and the outside radio frequency transceiver and the inside radio frequency transceiver are in wireless signal connection. By the steering control system, steering of the swimming robot can be controlled flexibly, and the robot is stable in integral control performance and has practicability.