NOVELTY - Preparation of copper indium gallium selenide (CIGS) solar battery buffer layer comprises conveying plating solution in pressurizing metering pump into from plating solution inlet pump pipeline to plating solution outlet pump pipeline, spraying to substrate by plating solution nozzle connected with plating solution outlet pump pipeline for 5-60 minutes, washing substrate plated with solution in deionized water, moving washed substrate into drying oven in production line conveyance belt, and forming II-VI compound film with 10-200 nm thickness.    USE - Method for preparing copper indium gallium selenide (CIGS) solar battery buffer layer (claimed).    ADVANTAGE - The method utilizes pressure-increasing metering pump to control the spraying of the plating solution, thus II-VI compound film obtained by spraying can be guaranteed in thickness, homogeneous degree and density; and has low cost.    DETAILED DESCRIPTION - Preparation of copper indium gallium selenide (CIGS) solar battery buffer layer comprises heating plating solution comprising 0.001-0.01 M cadmium salt or zinc salt, sulfur resource 1-10 folds of concentration of cadmium salt or zinc salt, 0.001-0.03 M ammonium salt, and 0.001-0.01M ammonia water in plating solution heater, at 50-100 degrees C in thermocouple unit; selecting sheet-shaped or crimp-shaped glass, polyimide or metal foil as substrate, horizontally placing on production line conveyance belt, and heating substrate at 50-100 degrees C in thermocouple unit; and conveying plating solution in pressurizing metering pump into from plating solution inlet pump pipeline to plating solution outlet pump pipeline, spraying to substrate by plating solution nozzle connected with plating solution outlet pump pipeline for 5-60 minutes, washing substrate plated with solution in deionized water, moving washed substrate into drying oven in production line conveyance belt, and forming II-VI compound film with 10-200 nm thickness.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic diagram of the preparation of copper indium gallium selenide solar battery buffer layer.