The invention discloses a 
system and a device for controlling 
pulse width modulation (PWM) output by an intelligent terminal. The 
system and the device for controlling the PWM output by the intelligent terminal is capable of controlling switch-on and switch-off of a power source and adjusting output power in a long-range and intensive mode. The 
system for controlling the PWM output by the intelligent terminal is composed of an 
intelligent control module, a radio network gateway module and a PWM sub 
machine controlling module which are connected together. The device is provided with a 
smart phone, a radio network gateway controller and a PWM sub 
machine controller. The 
smart phone and the radio network gateway controller are connected through a 
wireless fidelity (WIFI) network. The radio network gateway controller and the PWM sub 
machine controller are connected through a 
wireless sensor network. Compared with the prior art, a structure of the 
intelligent control module, the radio network gateway module, the PWM sub machine controlling module is adopted, the 
smart phone is operated to control the PWM sub machine controller to output a PWM 
analog signal, 
voltage of an adjustable 
voltage device and output power of the adjustable 
voltage device are controlled, and a plurality of devices with 
electricity and power adjustable can be operated and controlled conveniently.