Preparation and application of hyperbranched composite system for plugging big pore channel

The invention relates to preparation and application of a hyperbranched composite system for plugging a big pore channel. The hyperbranched composite system comprises solution of suspension dispersive agent with mass concentration of 0.3 percent to 0.4 percent, nucleocapsid with mass concentration of 3 percent to 5 percent, solution of flocculation agent with mass concentration of 2 percent to 4 percent and injected water with mineralization degree of 3,000mg/L to 30,000mg/L. A preparation method of the hyperbranched composite system comprises the following steps of: placing the injected water into a reactor; slowly adding the suspension dispersive agent into the reactor at a stirring speed of 680 to 720r/min; after stirring for 30min, reducing the stirring speed to 380 to 420r/min; after continuously stirring for 1.5 to 2 hours, obtaining the solution of suspension dispersive agent; adding the nucleocapsid into the solution of suspension dispersive agent; stirring for 15min at a stirring speed of 680 to 720r