The invention discloses a composting method used for increasing humic acid content through phased adding of humic acid precusor substances. The composting method is used for solving a problem in the prior art that humic acid content is not high. The composting method comprises following steps: 1, protein organic waste and fiber organic waste are subjected to composting, at composting temperature increasing period, MnO2 is added, and a low concentration polyphenol waste is added; 2, before composting high temperature period, in each time of overturning of the protein organic waste, a sugar containing waste, a polyphenol waste, and a carboxyl waste are added, in each time of overturning of the fiber organic waste, the protein organic waste and the carboxyl waste are added; 3, at composting high temperature period, a humic acid containing precursor waste is packaged with textile bags, and is embedded in high temperature period compost; and 4, at composting temperature reduction period, ahumic acid containing precursor waste processed through harmless treatment is added into compost for at least one time. The composting method is used in the field of composting.