The invention provides a method for identifying the type of drilling fluid and a method for identifying the type of drilling and completion waste. The method for identifying the type of the drilling fluid comprises a step of measuring liquid phase fraction and asphalt content of drilling fluid to be identified, wherein the drilling fluid to be identified belongs to polymer drilling fluid or sulfonated drilling fluid, a step of obtaining drilling fluid filtrate of the drilling fluid to be identified and measuring the sulfo group content of the drilling fluid filtrate, a step of determining thesulfo group content of the drilling fluid to be identified according to the liquid phase fraction of the drilling fluid to be identified and the sulfo group content of the drilling fluid filtrate, anda step of determining the type of the drilling fluid to be identified according to the sulfo group content and the asphalt content of the drilling fluid to be identified. According to the identifyingmethods provided by the invention, the type of the drilling fluid and the type of the drilling and completion waste can be accurately judged, and so the drilling and completion waste can be treated in a targeted manner. Moreover, the whole identification process can be completed through an indoor experiment, the influence of human factors is small, the reliability is high, and the repeatability is good.