Over the past years, two dimensional (2D) graphitic carbon nitride nanosheets (CNNs) have attained increasing interest in the study of graphitic carbon nitride (g-C3N4) due to their superior physical-optical properties as photocatalyst. More and more researchers attempt to design photocatalytic systems based on CNNs to realize the control of photocatalyst morphology for enhancing performance. Hence their combination with zero dimensional (0D) nanomaterials, which frequently serve as guest materials, has witnessed great progress. Therefore this review introduces the latest fabrication strategies of CNNs based on conventional strategies and firstly summarizes their photocatalytic properties systematically. More important, typical advanced examples combining CNNs with 0D nanomaterials like carbon nanodots, noble metal atoms and semiconductor nanoparticles are presented for their characteristic 0D/2D nanostructures, which have never been reported in any previous reviews up to now. Their preparation, photocatalytic mechanisms and performance influence factors are deeply discussed. In addition, three kinds of multicomponent complex systems, which take advantages of 0D nano-materials/CNNs ingeniously, are elaborated on their charge-transfer pathways in our review. Finally, the current challenges and development ideas of 0D nanomaterials/CNNs systems in photocatalytic applications are proposed. This review enriches the knowledge in the applications of CNNs and paves road to the combination of 0D materials with CNNs and even other 2D materials.