Production method of catalysis layer

The invention relates to a production method of a catalysis layer, and concretely relates to a production method of a fuel cell or water electrolysis catalysis layer. The method comprises the following steps: dispersion liquid preparation: stirring and dispersing 100 parts by weight of a catalyst precursor, 10-200 parts by weight of a binder and 1000-10000 parts by weight of a solvent to obtain a dispersion liquid; and catalysis layer production: spraying, brushing or screen-printing the dispersion liquid on a current collector or a diaphragm, reducing at 100-400DEG C in hydrogen atmosphere, and washing to form the fuel cell or water electrolysis catalysis layer. Or the method comprises the following steps: dispersion liquid preparation: stirring and dispersing 100 parts by weight of a catalyst precursor, 10-200 parts by weight of a binder and 1000-10000 parts by weight of a solution of a reducing agent to obtain a dispersion liquid; and catalysis layer production: spraying, brushing or screen-printing the dispersion liquid on a current collector or a diaphragm, and washing to form the fuel cell or water electrolysis catalysis layer. The method simplifies the production process; and the catalysis layer can be continuously produced, and the combination degree and the durability of the catalysis layer can be further improved through optimizing the production process.