The invention discloses a method for preparing carbonyl ferrocene condensed 2-amino-5-substituted-1,3,4-thiadiazole. The method comprises the following steps: adding A mol of carbonyl ferrocene, B mol of 2-amino-5-substituted-1,3,4-thiadiazole and C mol of p-toluenesulfonic acid into a dried mortar, grinding at room temperature until the raw material reaction (a TLC monitoring reaction) is complete, preserving the temperature in a drying box under the condition of 50 DEG C for 30 minutes, cooling to room temperature, adding absolute ethyl alcohol, performing suction filtration on the mixed solution, removing the catalyst p-toluenesulfonic acid, performing vacuum concentration until the filtrate is dried, thereby obtaining the crude product, wherein the ratio of A to B to C is 1:(1.0-1.2):(1.0-1.2); and recrystallizing the crude product by using absolute ethyl alcohol, thereby obtaining the purified product. The method disclosed by the invention is short in reaction time, mild in reaction conditions, low in equipment requirements, easy to operate and simple in after-treatment and is a green, economic, environment-friendly and high-efficiency method for synthesizing the carbonyl ferrocene condensed 2-amino-5-substituted-1,3,4-thiadiazole, a solvent is not needed, the catalyst can be repeatedly used, and the yield is over 85 percent.