The invention relates to an acrylamide salinity and heat tolerance fluid loss agent for drilling mud. A production method comprises the following steps: weighing a certain amount of each monomer according to feeding ratio, putting dissolved methacrylic acid into a reaction container, heating to 45+5 DEG C, adding N, N-dimethylacrylamide dissolved by water, adding more water to specified proportion, heating to 130 DEG C, stirring for 20 minutes, finally adding acrylamide, stirring, after sealing general N for 230 minutes, adding 0.5 percent of sodium thiosulfate initiator, regulating pH to 8.5 through potassium hydroxide, continuously reacting for 6 hours, stop reacting, and cooling to room temperature to obtain a greenish black product. The invention provides the acrylamide salinity and heat tolerance fluid loss agent and the production method thereof, so that the defect that the conventional fluid loss agent has poor salinity and heat tolerance is overcome, and better filtration reducing property can be realized event under the condition of 120 percent of saline basic mud and 150 DEG C hot rolling.