Positive Pleurotus ostreatus reference substance containing total mercury and preparation method thereof

Provided is a positive pleurotus ostreatus reference substance containing total mercury and a preparation method thereof. The preparation method comprises the following steps in sequence: a) pleurotusostreatus culture medium is prepared and cultured at room temperature; b) mercury standard solution is added into the culture medium and uniformly mixing is carried out; c) culture medium is sterilized; d) pleurotus ostreatus strain is inoculated in the culture medium; e) pleurotus ostreatus strain is cultivated into pleurotus ostreatus body; f) the pleurotus ostreatus is harvested, dried and grinded; and g) the total mercury content of the obtained dried pleurotus ostreatus powder is determined. The edible fungus reference material with required total mercury content can be designed and obtained by using the invention, and the method can be used for organizing the national capability verification, and then the total mercury and the speciation analysis reference material in the food matrix can be developed and ma