The invention provides a preparation method of a ferrocene-based conjugated microporous polymer. The preparation method includes the steps that 1, 5-15% of a first construction unit, 10-20% of a second construction unit, 0.1-0.5% of a catalyst, and 75-85% of a dispersing medium are sequentially added into a container, ultrasonic dispersion is conducted for 30 minutes under the protection of inert gas, the inert gas is fed in a filled mode, freezing, air sucking and unfreezing are conducted and circulated three times, the temperature is slowly raised to 65 DEG C within 2 hours, and a thermostatic reaction is conducted for 72 hours; 2, after the reaction is ended, filtration is conducted, and washing is conducted with chloroform, distilled water, methyl alcohol and acetone four times; 3, Soxhlet extraction is conducted with methyl alcohol for 48 hours, and a product is subjected to vacuum drying for 24 hours at the temperature of 70 DEG C. A one-step method is adopted for preparing a ferrocene-based conjugated microporous polymer high molecular material, and the material has a high BET surface area and pore volume, good chemical stability and thermal stability and has potential application value on the aspects of adsorption, sewage treatment, catalyzing, gas separation, gas storage and fluorescence sensing.