The invention relates to a polysubstituted phenylquinoline platinum (II) complex which is expressed in the structural formula shown in the specification. The complex is prepared through the following steps of: utilizing a C bidentate ligand-2-aryl-polysubstituted quinoline to react with potassium chloroplatinite so as to obtain a platinum (II) chlorendic dimmer of the corresponding ligand, and utilizing the platinum (II) chlorendic dimmer to react with acetylacetone so as to prepare the complex. The target platinum (II) complex prepared by the method can serve as electroluminescent phosphorescent materials and doped phosphorescent materials to be applied to organic electroluminescent devices, and the substituent groups of different electron-withdrawing groups and electron-donating groups are introduced so as to regulate the phosphorescent light color of the target complex, so that the complex can emit from yellow lights to orange yellow lights and orange red lights.