The invention provides an intelligent well mouth desulfurization integrated device and method. The device comprises a well mouth gas inlet, a separation heater, a triazine solution desulfurization tank, a fuel gas liquid separation tank, an online H2S monitor, an intelligent control system, a well mouth blowdown system and a well mouth output system. The well mouth gas inlet is connected with upper end inlets of the separation heater, the well mouth output system and the well mouth blowdown system, an upper end outlet of the separation heater is connected with the well mouth blowdown system and a lower inlet of the triazine solution desulfurization tank separately, and the upper end outlet of the separation heater is connected with an inlet of the triazine solution desulfurization tank. The device can achieve instant and rapid desulfurization of sulfur-containing natural gas; automatic detection of the H2S content in natural gas before and after desulfurization can be completed throughan online H2S detection system; the natural gas separation and heating control process can be completed through the separation heating device, and the triazine solution reaches the best desulfurization reaction temperature; remote positioning and operation state monitoring of the device can be completed through the intelligent control system.