Objective To study the internal relationship between resting tremor and slow response in patients with Parkinson’s disease. Methods The movement characteristics of wrist joints in valgus direction was studied by dynamic modeling on wrist joints of the upper limbs. The system delay concept was introduced with human autonomous control and the sensory delay characteristics of Parkinson’s patients was simulated, to make stability analysis and dynamic response of the involuntary wrist movement. Results The stability analysis and numerical solution of this time-delayed control system showed that when the sensation was delayed to a certain extent, involuntary tremor of wrist joints in patients with Parkinson’s disease would happen, which conformed to resting tremor from Parkinson’s disease. Conclusions Resting tremor from Parkinson’s disease is caused by sensation and movement delay.