Control valves are used to reduce the pressure of compressed air according to the input signal and are widely used in automation production facilities and industries. The control valve produces PWM and PDM signals according to the difference between the set pressure and the outlet pressure, and based on this, the internal solenoid valve is operated to control the compressed air pressure. The threshold level of the PWM and PDM signal is determined by the dynamic performance of the internal solenoid valve and is known to affect the performance characteristics of the control valve. However, until now, the study on the threshold level of the control valve has been insufficient. Therefore, in this paper, the relationship between the response performance of the internal solenoid valve and the threshold level is experimentally evaluated and the results are presented.