Nutrient salt culture medium for promoting microbial oil production

The invention relates to a nutrient salt culture medium for promoting microbial oil production. The culture medium comprises the following components: a nitrogen source, a phosphorus source, a pH value buffering control agent, a microelement balance regulator, an osmotic pressure regulator, and a natural raw material extracted solution comprising a cavings extracted solution and a pin needle extracted solution. A preparation method for the cavings extracted solution comprises the following steps: adding 5-10 wt% of cavings into 1-5wt % of a sodium carbonate solution, heating the mixture for 10-20 minutes' boiling, and carrying out filtration to obtain the cavings extracted solution. A preparation method for the pin needle extracted solution comprises the following steps: adding 2-5 wt% of dry pine needles into 1-5 wt% of a hydrochloric acid solution, heating the mixture for 5-10 minutes' boiling, and carrying out filtration to obtain the pin needle extracted solution. During the application of the culture medium, certain microelements also can be added into the culture medium according to the geological characteristics of different oil production areas, so as to facilitate harmonious growth of microorganisms.