The invention discloses a porous organic polymer having a repeating structure unit showed as formula 1. The invention also discloses a preparation method and application of the porous organic polymer.The invention further provides a solid catalyst for gold nanoparticles supported by the porous organic polymer, a preparation method of a solid catalyst and application of the solid catalyst in catalyzing a nitro compound to generate an amino compound. The invention provides a one-pot method which is simple and efficient and is used for preparing a composite material for the gold nanoparticles supported by the organic polymer in an environment-friendly manner. The method can be applied to industrialized scale production. The composite material disclosed by the invention has high efficiency catalytic activity and selectivity when being applied to catalytic reduction of 4-nitrophenol. The conversion rate of the composite material is as high as 99 percent and the reduction reaction rate is high. After the material undergoes 5 catalytic cycles, the conversion rate of the material still reaches 95 percent.