The present invention relates to black active dyes and the preparation of the same, and 2,4-biaminobenzene sulfonic acid sodium, H acid, 2,3-bibromopropionyl chloride and dinitroaniline are used as the prime starting materials. Through the process of condensation reaction, diazo-reaction, coupling reaction and post treatment. When adding appropriate of red compositions or orange compositons, hight jet black active black product can be obtained, when using it can stain without adding any heave metals as the addtivites, it can replace the acid mordant black PV used for staining the cashmere and other worsted fabric, it also can be used for staining the fiber, such as cotton, silk, polyamide and so on. The method avoid the product of printing and dyeing wastewater containing heavy metal Cr6 + , and promote technological progress of printing and dyeing fields.