In this paper,a control system of a mining device,which can adapt to the tiny-terrain of ocean cobalt-rich crusts,is designed.The control system consists of five units: hydraulic unit,terrain detecting unit,communication unit,control and display unit,and data storage unit.A parameter fuzzy self-adjusting PID controller for the control system is also studied.Simulation indicates that the overshoot and setting time of step response of parameter fuzzy self-adjusting PID controller are obviously lower than that of the normal digital PID controller,and it is of better dynamic and static properties and strong self-approaching ability.