The invention discloses a process for producing a high-power light emitting diode (LED) substrate. The process comprises the following steps of: (1) adding 5 to 30kg/m<3> nano diamond powder into common electrolyte; and (2) controlling the temperature of the electrolytic mixed solution to be between 40 and 50 DEG C, putting a substrate material into the electrolyte, performing conventional chemical plating, dispersing the electrolyte by adopting ultrasonic wave in the plating process, and mechanically stirring the electrolyte at the same time so that the diamond powder is uniformly suspended in the plating solution. The LED substrate produced by the process has better heat dissipation performance, the reflectivity and the luminous efficiency of the LED substrate are improved, and the process is simple and convenient to manufacture.