The invention discloses a luminescent complex. The chemical formula of the luminescent complex is [Cdx(C8HyO4)(C4H5N3)0.5(H2O)z], wherein the x value is 0.5-1, the y value is 10-11, and the z value is 0.5-1.5. A luminescent complex product is stable, can be exposed in air and is non-degradable and non-deliquescent, and a photoluminescence test result indicates that the prepared luminescent complex has higher luminescent intensity in an ultraviolet region and has great potential application value in the field of visible light materials. A preparation method of the luminescent complex is induced and controlled by a pH regulator, is simple in process and high in yield and has repeatability, and a PXRD (power X-ray diffraction) result shows that the prepared luminescent complex is higher in purity and is suitable for large-scale production, and a new research approach is provided for controllable synthesis of the luminescent complex.