The new type of excavator based on multi degree-of-freedom controllable mechanism is a typical nonlinear multi-input-multi-output (MIMO) system, of which the closed chain constraints make it with strong coupling relationships. Consequently, the classic PID control method is not able to satisfy the control demands of the system. This paper introduces a fuzzy adaptive PID control method focusing on the improvement of the control accuracy of the excavator based on fuzzy logic inference according to the actual response of the control system, aiming at the automatically online adjusting of the PID parameters. A simulation study is also proposed. The correctness and validity of the project is verified by comparing the simulation results of the fuzzy adaptive PID controller with those of the classic PID controller. Results show that the former one designed for the new mechanical excavator has shorter settling time, and with less overshoot, than the latter one.